Cass had done a good job parking his truck far enough off the road that the trees mostly screened it and prevented it from being noticed by people driving by; Dean would have driven right past it had Cass not suddenly sat up in the back of the Impala and barked to warn him. Pulling Baby in beside the truck, Dean put it in park and looked around. It was a very picturesque area, huge redwoods, crisp air, rich earth, stunning greenery. All of it was lost on him, because it was also a worthy place to set up an ambush, and that was what he was most concerned about, even though he knew that there was no reason for the Angel that had assaulted Cass to still be around.

After they'd sat eyeing the shadows under the trees suspiciously for several minutes, Sam broke the ice, saying, "Well, I guess we'd better have a look around."

They got out, and Dean was careful to attach the six-foot leash to the leather collar Cass was now obligated to wear. Putting the leash on made Dean feel slightly sick to his stomach. It was no way to treat his best friend. But the alternative was that Cass ran out into the road the first time a motorcycle went by and got himself hit by a truck, and Dean wasn't sure there was enough Angel juice left in the furry canine body to survive that.

Cass immediately went to the end of the leash, aiming himself into the woods. He stopped, looking over his shoulder, and Dean realized for the first time that the attack hadn't happened here by the road, but somewhere else, deeper into the woods. Dean didn't really want to go stomping around in the woods, especially not when he got a sudden flashback to a wendigo hunt over a decade previous.

It was a different forest, he was practically a different man, and the hunt certainly hadn't involved Angels or even Angel-dogs (or in fact any dogs at all). But it had ended up with him underground, bleeding and wondering if this time he might finally be going to bite the dust. He had known so little then. Nothing about Heaven, Hell, Lucifer, Angels, God, The Darkness or any of it. Hard to believe he'd ever been so naive as to think that it was a mere wendigo that was gonna get him. He should get off so easy. Back then, death had a grim finality to it. But life had also been simple.

Shaking off the memory, Dean adjusted his grip on the leash to free a hand in case he needed to go for his gun, the Angel blade he was carrying… or just his fake ID. And then he started off, letting Cass dictate the way. Sam waited for Mom to catch up and park, and then they both followed.

For a good mile, Cass led the way, never pausing or varying in his straight course into the woods. And then, quite abruptly, he halted and sat. Dean looked around, but this spot looked very like several others they'd already walked past. Trees, dirt, forest shrubberies. Nothing indicated an Angel fight, or even any kind of fight at all. If this was where Cass had been dogged, there hadn't been much in the way of struggle. Dean wondered why that was, but he didn't ask.

"You're sure this is the spot?" Mom asked.

Cass tilted back his ears and blew through his nose, insulted by the very question. No longer able to conceal anything he felt, including offense, he refused to answer.

"Hey, look at this," Sam had knelt and brushed aside some dead leaves, uncovering an unusually large feather of pure white.

"What is that?" Mom inquired, though she looked like she already suspected.

"An Angel feather," Sam replied, and then cast a significant look at Dean, "A secondary, I think."

Dean frowned and shook his head, "No, that's not possible. You've seen the wing shadows. There's not an Angel around with a full set of feathers, certainly not secondaries."

"What do you mean?" Mom had never seen an Angel's wing shadow, and Dean had sort of skipped the story about the Fall for the most part, especially the ragged state it had left the Angels' wings in.

"You ever wonder why Cass doesn't fly?" Dean asked.

"Not really," Mom admitted, "I assumed the wings were metaphorical."

"Yeah, well, they're not," Dean told her flatly, "They may not be visible, but they're very real."

"But broken," Sam interjected, "Only Lucifer can still fly."

"And I bet he's got his secondary feathers too," Dean said, turning to Cass, "Don't tell me that son-of-a-bitch found his way out of the cage. Again."

No.

"Okay, so what the Hell?" Dean wondered, turning back to Sam and the mystery feather, "What kind of Angel would still have secondary feathers? And what kind of Angel just casually sheds 'em?"

"What kind of Angel could take out Cass without a fight?" Sam countered.

"Dammit," Dean hissed through his teeth, "Now we've got more questions and exactly squat for answers."

Sam was frowning more deeply as he ran his fingers along the vane and barbs of the feather, "Dean, there's something… something weird about this feather."

"You mean besides the fact that it didn't come from Lucifer or any Angel we've seen since the Fall?" Dean asked irritably, though he was not so much annoyed with his brother as the whole situation.

"Yeah," Sam said, then came over to present the feather to Dean, "Here, look at it. I'll admit, I haven't seen that many physical Angel feathers, and certainly not the bigger ones but… the shape of it doesn't match the shadow pattern of Angel wings, before or after the Fall. It's like the difference in a raven and an osprey, assuming both of them had white feathers."

Dean wasn't sure about ravens and ospreys, but Sam was right, the shape of the feather wasn't what Dean would have expected if the feathers in those shadow wings became solid reality. Of course, it was possible that the wings were different if they manifested physically, which they could presumably do seeing as there were spells that called for Angel feathers, and if the feathers could be real and solid, surely the wings could be too. But… well, that was neither here nor there. He turned to Cass.

"This isn't a regular Angel feather, is it?"

No.

"Okay, so did it come from an Archangel?" Dean asked, ignoring the fact that he only knew of one live Archangel, and Cass had already said it wasn't Lucifer.

No.

"A Grigori?" Sam guessed.

No.

They were running out of Angel types. Both Seraphs and most lower level Angels were covered by Dean's definition of 'regular,' since he hadn't noticed any difference in Cass's wings when he got his upgrade several years prior. And a Cherub? Taking on Cass? Having the power to turn him into a dog? Completely absurd. So… what then?

"But it was an Angel," Dean looked for confirmation, though he'd asked the question enough times.

Yes.

"An Angel with intact wings?" Mom ventured, a leap neither Sam nor Dean were able to make, because they knew too much about the Fall to even entertain the notion.

Dean was about to tell her that it was impossible, explain again that Lucifer was the only flighted Angel left, elaborating that this was because he was the only Angel that had intact wings to fly with. But before he could get a word in edgewise, Cass answered Mom's question.

Yes.

Feeling his eyes widen, Dean turned to look at Sam, and saw the same look of shock reflecting back at him from his brother's eyes.

An Angel with intact wings? How?

But they couldn't ask that. Yes and No were just not enough. No matter how many questions they asked, they were never going to get where they needed to go. Dean was beginning to understand Cass's despair back in the motel room a few days ago. Whatever went down, it wasn't simple to explain. An Angel with intact wings. What the hell did that even mean? The damage done in the Fall was permanent. Even Chuck, when he had repaired Lucifer (and more importantly Lucifer's vessel, which Cass had been filling the role of at the time) after Amara nearly tore him apart, had not given Cass back his wings.

"I have an idea," Mom said, then without waiting for anyone to ask her what it was, she explained, though the explanation seemed only to beg still more questions, "Scrabble."

"You want to play scrabble?" Dean asked incredulously, "Now?"

"No, Mom's got a point," Sam remarked, and then continued when Dean stared at him, waiting for something useful to follow that statement, "Cass can spell words, probably better than any of the rest of us, considering the number of languages he knows. Give him enough letters, and he can tell us what happened," he paused for emphasize, "Exactly what happened."

Dean pondered for a moment the simple brilliance of the notion, then he said, "Well damn, let's go play scrabble then."

The nearest town didn't seem to be big enough to have more than a basic grocery store, and that place certainly didn't sell anything like scrabble. They had to make their way south along the road, stopping at towns, looking for scrabble boards. Of course, they were looking for something out of fashion. There were apps for that, why would anyone buy a physical copy of the game? But they finally found a store that had what they were looking for. While Dean went for pizza for the Winchesters and appropriate food for Cass, Sam and Mom reserved a motel room, bribing the owner into letting them bring their dog, promising he wouldn't pee on the carpet and no he didn't have any fleas.

Dean returned to solemn faces, and letters scattered across the floor in no organized fashion. Cass was padding around among the letters, pushing them with his nose in seemingly random directions.

"So?" Dean asked, setting the pizza down on the table.

"Well..." Sam hesitated, looking at Mom uneasily, but she shrugged helplessly.

"What? He can't spell anymore?"

Sam chewed his lip and made one of his more elaborate unhappy faces, before saying hesitantly, "That's… not exactly the problem."

"So what, exactly, is the problem?" Dean demanded, in no mood for games, despite the fact that they had just purchased one less than two hours ago.

"We asked him who turned him into a dog," Mom said.

"And?" this was getting to be like pulling teeth.

"And he used two letters," Sam told him, "He used an M. And an E."

"Cass turned himself into a dog?" Dean asked, dumbfounded.

"That's what I asked him," Sam said, "And..." he sighed, gesturing at the collie endlessly circling and pushing letters around, "He's been doing that ever since."

"Okay," Dean said, feeling the need to take control of this situation, which seemed to be rapidly getting out of hand. He clapped his hands, "Cass!" his call had the desired effect, Cass stopped and looked up. Demandingly, Dean inquired, "Did you do this to yourself?"

Yes. A pause. No.

"Well that's enlightening," Dean muttered sarcastically.

Cass resumed his letter pushing. Dean cursed himself for his derisive tone. Cass didn't need that. Of all things of which he had no need, that was the thing he needed the very least right now. Cass wasn't trying to be difficult, he was simply unable to be anything else at the moment. He was not merely wounded, not merely changed, he was actively fragmenting at his core, not only becoming something he was not, but also someone he was not. And it wasn't his fault. Dean didn't believe for a minute that it was truly Cass's fault. But they needed something more than Cass had offered.

"Cass," Dean spoke firmly, but this time Cass did not look up, so he softened his tone, "Cass?"

But Cass continued shuffling for several seconds, until he had five letters arranged.

O. T. H. E. R.

"Other?" Sam wondered, "Other what?"

Cass found the M and E he had used earlier, and put them under Other. He looked at Sam, then Dean, sternly expectant. It had taken him effort to make this statement, and they were not doing very well at meeting him halfway on it.

Recognition came into Sam's eyes as he made a tremendous mental leap, "An alternate reality."

"What, you mean like that one where you were Polish?" Dean asked, at first jokingly, then as he thought about it, it seemed to make sense.

"If there's one alternate reality, there's probably hundreds, thousands maybe," Sam said, "And if there's one where Angels don't even exist…"

"Then there may be one where Cass is a dick who likes to turn other Angels into every mailman's worst enemy," Dean concluded when Sam trailed off, "Okay, but what the hell is Douche Cass doing here? What does he want? And why'd he do this to our Cass?"

Cass was shuffling the pieces again, but how long would it take him to get his message across? Suddenly, the available letters didn't seem like nearly enough.

"We're gonna need a bigger scrabble set," Dean remarked.

Diligently, Cass continued to shuffle pieces, though it wasn't at first obvious where he was going with his new word arrangement. However, now they had the thing by the root, getting at the answers was a lot easier. Cass hadn't found more than a D and an E before Sam made the leap that there was another Dean out there walking around too, at which point Cass abandoned that construction in favor of a new one. It was a slow, tedious process, this wandering around the floor looking for letters to push around with his nose, but Cass didn't break concentration or stop for anything until he'd spelled his next word.

S. E. A. R. C. H. I. N. G.

"Searching," Dean read it aloud, "Searching for what?"

Cass knocked aside the E and every letter after the A, and retrieved his M from the earlier message.

"Oh good, so alternate reality Sammie's here too," Dean nodded, "That's just great."

"Calm down," Sam said, noticing Dean was getting agitated, and that his agitation seemed to be making Cass nervous, "We don't know it's bad."

"We don't-" Dean broke off with a sharp sound that wasn't quite a laugh, "Their Castiel turned ours into-" he looked about ready to explode as he practically shouted, "-Into Lassie!"

Dean's final words had been accompanied by hand waving in Cass's direction. Abruptly ceasing his activity, Cass tucked tail to belly and cringed where he stood, staring at Dean as though he expected to be struck. He trembled, and seemed as though he wanted to crawl away and hide.

"Dean," Mom said with painful gentleness, "You're scaring him."

Turning to look at Cass, Dean saw the truth of her words. It flickered through his mind to wonder if his yelling always inspired terror in Cass and the Angel was just very adept at concealing it, or if this was the 'more fur than feathers inside' that Crowley had warned them about.

Calmly, Sam renewed the discussion, "We don't know. Dean, this could've been some kind of accident. Maybe they're just disoriented and scared. Think about all those times Angels toyed with us. Zachariah, Gabriel... We didn't know what was going on. If we'd seen ourselves in another reality, we probably would've freaked out. That other Cass and Dean, they might have thought they were just... defending themselves."

Dean wanted to shout some more, but instead he took a deep breath and tried to make himself relax.

"Yeah well," he said quietly, "That doesn't do us much good here and now, does it?"

Recovering from his alarm at Dean's earlier tone, Cass barked. It was a sound of deep frustration, of days upon days of it, of trying to be heard and having no one listen to him. And now they had the nerve to be upset over a few minutes' of consternation. The bark sounded like a rebuke, a scolding.

"So how do we find them?" Mom asked, seemingly missing the note in the bark even as Sam and Dean couldn't help but hear and be ashamed of themselves (though they would never admit it).

Cass barked again, but this time more like he was inviting them to pay attention.

It was sensing his other self that had gotten Castiel into this trouble to begin with. He could sense The Other still, but had thus far had no reason to follow up on that. He could do nothing by himself, and he could not have persuaded even a single Winchester, much less all three of them, to follow him blindly. But he could track the Angel from beyond, could feel him even now, sense where he was, find him anywhere.

Castiel pushed only two letters, the original two letters, the two letters that had caused all the fuss to start with.

M E