BTVS and Angel characters do not belong to me. I'm just borrowing them for a while.
Spoilers: Up until the Season 5 episode The Body (just to be safe).
At Dawn's scream Giles raced back into the room a few steps ahead of Joyce. As he threw open the door he noticed that Dawn appeared to be back to her normal self. He also noticed that the open window seemed to be the cause for her alarm. Leaving Joyce to tend to Dawn he quickly crossed the room to the open window and was just in time to observe a shadowed figured hurrying away from the house. A figure wearing a long black overcoat. He frowned and closed the window. "Dawn are you alright?" He flushed and averted his eyes when he realized that she was wearing what was left of her toddler pajamas. Mumbling an apology he hurried downstairs, leaving two giggling Summers women in his wake.
He looked around the living room, half expecting to see the children back to normal as well. He sighed and pinched the bridge of his nose before picking up the still four year old Buffy. "Dawnie?"
"Your sister is fine, Buffy. She um, she was just surprised." He had no idea how to begin to explain to a four year old that her younger sister was now much older.
"She cries a lot." Buffy said with some certainty.
"Well, um, yes. But she's fine." Giles reassured but Buffy had already lost interest. "Ow." Apparently her new fascination was pulling at the chest hairs poking out from his open shirt collar. Buffy giggled. If he wasn't mistaken she had a rather impish glint in her eyes. But surely he was imagining it. She wriggled in his arms indicating that she wanted down. He gladly placed her down on the sofa next to Willow and Xander who were engrossed in watching The Lion King.
Leaving Lorne to keep an eye on the children, Giles and Wesley headed into the kitchen. "Dawn is alright, then?" Wesley asked while pouring them both a cup of tea.
"Yes. She appears to have reverted back to normal. Hopefully once Joyce gets her settled down we can ask her a few questions. There must be some reason why she is the only one that changed back."
Wesley nodded. "It would help narrow down the research if she can recollect any of her experience. But I thought she was asleep? Did the transition awaken her?"
"I think there was someone outside her window. By the time I reached it they were gone, but I did catch a glimpse of a dark overcoat."
"Spike?"
Giles sighed. "No. Not that I think Spike is above that sort of thing, but the figure I saw running away had a larger build." He narrowed his eyes.
Noticing the Watcher's tightly clenched jaw, it didn't take any strenuous exercises in deduction to ascertain whom Giles thought the mysterious visitor had been. "You think it was Angel."
"Yes. He has a history of watching Buffy through her window. I don't think he meant to frighten Dawn, which is why he fled when she screamed. But with the way he has been behaving lately, I'm not comfortable with his having that kind of access to this house."
"Do you think he is a danger to the children?" Joyce asked from the doorway.
Giles began to pace. "Despite my not liking Angel, normally I would say no. But lately he has not been himself. Joyce, with your permission, I would like to perform the disinvite spell again."
"You never liked Spike. I hate you!" Dawn shrieked as she ran from the hallway.
The three adults stared open mouthed at the place where the teen had fled.
"She didn't mean that. She loves you." Joyce said watching the pained expression flit across Giles' face. She watched him school his expression and put his Watcher's face, as the children called it, back into place. She sighed and once again wished that her daughters had not inherited her temper. "Rupert, the disinvite spell will keep him from entering, but is there any spell that could keep him away from the upstairs windows?" She shuddered at the thought of Angel watching them all in their bedrooms.
"Not a spell, per se, but a good dousing of holy water should do the trick. I'll limit it to the upstairs window ledges. I'm not a fan of Spike, but I respect your right to decide who has access to the house, Joyce." He looked upstairs and Joyce was sure she detected a note of sorrow in his expression.
After he and Wesley performed the disinvite spell, Giles went upstairs to Buffy's room and retrieved the holy water from her weapons chest. He thoroughly doused the window sill and the roof just below and then repeated his actions for Joyce's windows. All that remained were the windows to young Dawn's bedroom. He knocked hesitantly on her door. "Dawn, may I come in please?"
"I guess," was her unenthusiastic reply.
He glanced over at her bed and noticed she was curled up and facing away from him, obviously still very upset with him. He took a breath to bolster his courage and said, "You're correct, Dawn. I do not trust Spike. But I do respect your Mother and her right to determine who has an invitation to her, your, home. A home that you should feel safe in, particularly in your bedroom. When did Spike start visiting your window?"
"What? My window, ewww! Spike hangs out on the porch or by the tree, but I've never seen him outside my window." She eyed the holy water that Giles was liberally sprinkling around the window sill and the roof below. Then it struck her. "Angel. You think it was Angel outside the window. Cuz' it was Buffy's room. You were talking about Angel downstairs not Spike."
"Yes, but the disinvite spell is rather inclusive. However, it will be up to your Mother to decide when and to whom she issues an invitation. The holy water is to ensure your privacy." He hesitated at the door as he was leaving, "I am sorry that I upset you, Dawn."
A teenage blur crashed into him before he turned the doorknob. "I'm sorry I said I hate you, Giles. I didn't mean it." She hugged him tightly.
He patted her hair gently. "Its alright, Dawn. I'm rather accustomed to the Summers women being angry with me." This earned the desired chuckle from the teen who released the Watcher with one final squeeze. "Get some rest and if you feel up to it tomorrow, perhaps you can answer some questions about your, recent, err, experience for me?"
"Sure Giles. Nite."
"Goodnight, Dawn. Sleep well."
When he reached the living room he discovered the other children had been put to bed and Buffy was standing by the couch in her pajamas and holding Mr. Gordo. He looked questioningly to Joyce.
"I think she's decided it is time for bed. There really isn't any use carrying her up to her room as she's only going to sneak back down here."
"But," he spluttered. He looked to Wesley and Lorne who were both grinning at him, clearly amused. He sighed and disappeared into the downstairs washroom to change into the sweatpants and t-shirt he was using to sleep in. As soon as he laid down on the sofa, Buffy crawled up and settled onto his chest like she had the night before. Mr. Gordo lie forgotten on the floor.
"Nite Giles."
"Goodnight, Buffy. Sleep well."
The next morning, Dawn had an interesting tale to tell. "God, it was so frustrating. In my mind I was saying, Mom, could I have a glass of water, but what came out was 'wawa'." She covered her face with her hands, still mortified at the memory.
Joyce grinned and pulled her into a hug, "don't worry, sweetie, you're still my little punkin' belly."
Dawn squirmed away. "Ugh, Mom. The other day that was cute, but now it just makes me want to wretch." At her mother's disconsolate look she added, "Next week I'll probably want to be your lil' punkin' belly again, but for now, can we ease off the baby talk?"
"Sure sweetie. Is sweetie ok?"
"Of course, Mom. Love ya. Now I should get ready for school."
"Dawn, Rupert and I think you should stay home today. Just to be sure that there aren't any other side effects." She glanced at Rupert. Or in case you wind up reverting back.
"Its just a precaution Dawn. Perhaps you can help your Mother and Lorne watch the others while Wesley and I do some research at the Magic Box?"
"Cool! I get to babysit Buffy?"
"Well, I think Buffy will be going with Rupert, but I could really use your help watching the others."
"I am so going to take a ton of pictures. Think of all the blackmail potential." Her mind was too busy scheming to hear Giles' objection, "err, Dawn that isn't precisely what your Mother had in mind."
With Dawn there to provide additional babysitting help, it was decided that only Buffy would go with Wesley and Giles to the Magic Box. This was after Giles had been unsuccessful in convincing Buffy to stay home and play with her friends.
"NO! I wanna go with you!" Lorne covered a grin as this exclamation from the tiny Slayer was accompanied by a little foot stomp.
"But Buffy, there aren't any toys at the Magic Box. Wouldn't you rather stay here and play with your friends."
"NO!" Again accompanied by a foot stomp. But what had been the Watcher's undoing was the tearful, "Don't you like me anymore? I'll be good I promise."
"Oh dear. Shh, Buffy. Don't cry. You can come with Wesley and I, alright? You know I'm very fond of you. Please don't cry."
At her "Yay! I win!" the Watcher knew he had been outmaneuvered once again.
They had only been at the Magic Box for a few short hours when Giles received a disturbing phone call.
"Rupert? Its Joyce. You need to come home right away."