Author's Note: Dear Readers, I must offer my apologies! Things got so crazy over the holidays that I completely forgot to post this final chapter! But here at last I give you the rest of the story. I hope you will enjoy! Katbybee and I had so much fun writing this together, and we hope you've had fun reading it as well. We wish you all the best in 2023!

•◊•◊•◊•◊•◊•◊•◊•◊•◊•

Herr Doktor Bockstein gestured toward the wall with his pistol and addressed Newkirk. "Stand there." When Louis came hurrying in with Hilda, he ordered the chef to stand by Peter. "The guards will arrive any moment," he told them. "So get me out of here before they come." He held up the box, which was cuffed to his wrist and turned the gun on it. "Fast, or I finish your friend."

Newkirk's eyes widened with shock, but he asked no questions. That would come later. He led the way to the tunnel entrance and pushed aside the stove to expose the trapdoor that led to the ladder down.

Bockstein put his pistol back in its holster and followed LeBeau down the ladder. Hilda, meanwhile, slipped outside to delay the guards' discovery of the general and Colonel Klink.

Newkirk made sure the stove and trapdoor were secure and then hopped off the ladder, wondering what was going to happen with the scientist next. To say the least, he was confused.

"You are sure we are safe here? They won't find us?" Bockstein asked, his voice trembling just a little.

Hogan had come up to them just then and held out his hand. "Newkirk, pick that lock. Get Andrew and Felix out of there." To Bockstein he said, "No guarantees until we get them out of there safe and sound."

"You don't need to pick the lock!" With his free hand, Bockstein produced a tiny key from his pocket. "You will need to figure out the combination on the lockbox, though. Burkhalter would not give it to me. He said he would open it when I was ready to work."

Newkirk smirked. "I can handle that… piece o' cake." He took the key and removed the cuff from the scientist's wrist. He then set to work on the combination lock.

Bockstein's forehead wrinkled. "I do not understand what cake has to do with it."

Hogan rolled his eyes but obliged the man. "It's just an expression. Never mind."

The scientist nodded. "I did not want to harm your friend. They have been forcing me to work on this project. I did not choose it. In fact, I released several of the mice they gave me to experiment on, just to delay things. Your friend must have found one of them and… well… apparently I was closer to success than I realized."

Newkirk opened the lock and reached inside, scooping up both Andrew and Felix. He pulled them gently out and checked them over. "They look okay, but it's a good thing we put that string around Andrew's neck, Guv. They're twins!"

"May I see?" Bockstein pushed past LeBeau to get a better look. He reached for the mice, but then got a look at Newkirk's hooded gaze and pulled his hands back. "The transformation is complete," he breathed out in awe. "When I saw them earlier, your Andrew still had one human foot."

Hogan scowled. "What do you want? It's your fault Carter is in this mess."

"I want to keep this whole process out of Nazi hands," Bockstein insisted. "It's too dangerous for them to have this knowledge. If word spreads that I succeeded, they would kill me and then take my work for themselves and use it against the Allied forces."

Hogan nodded. "Frankly, it's too dangerous for the Allies to have either. Can you change Carter back?"

"I don't know!" Bockstein raised both hands in the air. "This is the first time any transformation has been successful, and I don't even know why! Back in my lab, it was not working. I coated the mice with a secret compound, but my human subjects did not change. Then I let the mice go."

"Then it must be something in Carter's lab that made the difference. You find out, fix him and we will get you out of here, as long as you destroy the compound after you fix Carter back up."

"My life will be worth nothing here," Bockstein whined. "I will tell you where my lab is. All my notes and supplies. Can't you destroy it and get me out of the Reich? I will do whatever I can for your friend."

"Deal. Fix this and you're on your way."

Bockstein breathed out a sigh of relief. "I will see what I can do."

"I think I can help with that," Wilson called out, coming up on the small group. "I isolated the chemicals Andrew was working with and discovered mouse hair had been mixed into it. He must have inhaled that and it sparked the change. Newkirk, if you can get me some of Carter's hair from his comb, I'd like to try using that to change him back."

"Oh, but you will need the compound first!" Bockstein declared. He rattled off directions for the men to find his lab. Meanwhile, Andrew skittered up Newkirk's arm and then nestled right up to his neck. Felix took up the same position on the opposite shoulder.

Hogan sent several of the men to find and retrieve the compound. They would destroy the lab later, in case it didn't work the first time and they needed to go back for other supplies.

That evening, their mouths and noses well protected, Wilson and Bockstein coated several strands of Andrew's hair in the secret compound. Then Bockstein cut the hair into tiny pieces and mixed it into the combination of chemicals Wilson had prepared.

Then they looked to the two mice and Wilson's eyes widened. Andrew was no longer wearing the string around his neck! Whether Felix had nibbled through it or it had just fallen off, no one could know. But it was gone, and there was no way to tell the two mice apart. They both sat on the worktable, munching on strudel crumbs, oblivious to what was happening around them.

"Newkirk," Wilson called. "Can you tell them apart? Cover your mouth and nose before you come in."

Newkirk pulled out his bandanna and covered the lower half of his face before he stepped into the lab. He looked at the two mice. "Blimey! They really are twins! I can't see any differences!" He thought for a minute. "Well, I guess you just have to use that stuff on both of 'em. You're bound to get it right with one of 'em. Maybe it won't affect Felix."

"Something else to consider," Wilson said, scratching his ear. "You said Carter got small first, then started to change, right? We need to be prepared in case we have a couple of human-sized mice running scared. I'll just do one at a time. If we get Andrew the first time, we'll leave Felix be." He nodded to Peter. "You choose one for me."

Peter couldn't tell at all which one was his friend, so he just randomly pointed to the mouse on the left.

Wilson nodded as he took a bit of the mixture he had prepared and put it in a miniature nasal syringe. He picked up the mouse Peter had indicated and squirted a puff of the mixture into its tiny twitching nose, then quickly set it on the floor.

The mouse sneezed once, and then suddenly began to expand in size. Before long, it was as tall as Andrew had been, though still in mouse form. It stood in one place, trembling in fear as it looked around from its new height.

"Now I suppose we wait," Wilson said. "The transformation took several hours before, but it worked from the top down. We should know something more by the time his head has changed."

Bockstein had staggered backward when the mouse grew. But now he stepped closer, murmuring in comforting tones. Soon he had the animal calmed down and no longer trembling. "I believe this is the true mouse," he said quietly, keeping his tone soothing. "There is no understanding in its eyes."

Newkirk stared at Felix. "What 'appens to 'im now?"

"If it works as it did before, he'll continue to change until he is a twin of your Andrew. We'll only know when the change is done. Look… see his fur changing on his head? What color was Andrew's hair?"

"Blond. Sandy blond."

"Yes, the color is changing first, and it's growing longer." Bockstein brushed a hand across Felix's head. "Do you see the texture has changed?" He nodded to Wilson. "I think you should change the other one as well. My guess is he will transform first and then grow, in reverse order from the initial transformation. Quick though — take some fur from Felix before it's lost. Then you can change him back. I think he'll be happier in mouse form."

Wilson took the fur as requested and set it carefully aside for later. Then he repeated the process for transforming Andrew.

As Bockstein had predicted, Andrew did not grow at first. Instead, he began the slow process of returning to his original form. First his hind paws changed shape, gradually becoming human feet. The change took a few hours to be complete, though he was still in miniature form. Wilson covered him with a blanket for his privacy, as his clothes had been lost at some point in the original change. At last, they saw the tiny form under the blanket begin to grow.

Andrew's head soon poked out from the top and he smiled up at them as he sat up, pulling the blanket around him. "What are you all doin' down here?" he asked. "Guess I fell asleep — I've been havin' the craziest dream!"

Newkirk smiled back. "Not a dream, mate. Wait till these two explain it to you!"

Before anyone could explain, Andrew turned his head and caught sight of Felix, who was by this point mostly human. He was sitting on the ground, also covered with a blanket. A couple of mouse paws stuck out under the edge of the blanket, and one long tail poked out behind him. He stared at Andrew and then a smile broke across his face, but he said nothing.

"Wha…" Andrew shook his head, his jaw dropping till it just about scraped the ground. "It… it's not possible! Is that… Felix?"

"It sure is," Hogan said. "He hasn't spoken a word. I'm not sure how much he understands, but he sure seems to recognize you."

At that, Andrew twitched his nose. Suddenly, without any delay at all, he had changed back to mouse form. He scurried across the lab and climbed up Felix's arm to chitter in his ear. Felix bent his head, listening carefully, and then gave a slow nod. Andrew scurried back down, under his blanket, and a second later, he was in human form again, a broad smile on his lips. "Wow! This could really come in handy!"

"Handy," Felix echoed, his eyes fixed on his twin.

"You'd better get us some clothes," Andrew said to Newkirk. "We can't just go around wearin' blankets, after all." He nodded towards Felix. "I got myself a twin brother. I wonder what Mom'll have to say about that."

Hogan groaned, "I wonder what Klink is gonna say about it. We can't hide him all the time. This is gonna be interesting."

Andrew shrugged. "Why can't ya hide him? If I can change back an' forth, surely he'll be able to too, won't he? Let 'im be on two legs when we need a fifteenth man or I'm out on a mission, and on four the rest of the time… if he wants to, that is."

Hogan nodded. "Yeah, I suppose that would work, I was just looking at the two of you as humans at the moment."

Bockstein nodded. "Look. Felix's transformation is complete." Instead of mouse paws, two feet now stuck out from under the blanket. "Treat him again with the mixture, only with the mouse fur in it instead of the human hair," he told Wilson. "Make sure it has plenty of the secret compound on it first, of course. We will see if he can shift as Andrew can now."

Wilson approached Felix with the nasal syringe — a full sized one this time. He was about to do the treatment, but Felix shied away from him. At that, Andrew (now clothed) shifted again and ran up to sit on his shoulder and chitter in his ear. With his friend's encouragement, Felix allowed Wilson to give him the treatment. The medic puffed the mixture into his nose. Over the next couple of hours, he went through the transformation back to his mouse form. Andrew stayed with him the whole time. Then, when it was done, mousey Andrew squeaked at him. Felix twitched his nose and then shifted in a flash to human form. Andrew did the same. He looked himself up and down and grinned. "Sure glad my clothes stayed with me this time!"

It took some time to teach Felix about being human, and he generally preferred his mouse form, but he learned to speak and over time he became a real whiz at playing poker. He and Andrew quickly became as close as any twins. The pair were handy to have on missions because they could easily evade detection. Andrew was often known to sneak into Klink's office and listen in on conversations when the coffee pot radio wasn't working. Most of all, they loved to pull pranks on their pals in the barracks.

Peter wasn't quite sure what to think about the new situation. Andrew was still his best mate, but Felix was a different matter. The two didn't quite mesh as far as personalities went. Because as far as Newkirk was concerned, Felix didn't have one. Andrew assured Peter that Felix would learn and get better with time, but Peter had a hard time with the idea that Felix really was still a mouse. But a nice enough one at that, so he tried hard to get along with him.

As for Felix, Peter had saved his neck, and therefore could do no wrong. He had a bad case of hero worship. Which made things really funny for the others to watch how Felix acted around the surly Englishman. No matter how grumpy Newkirk was, Felix never got bothered by it. He was always sunny and serene… even more so than Andrew. Which drove Newkirk up the wall. Almost as much as when Felix beat him in poker.

As for Andrew's family, Andrew was pleased to get a letter from home assuring him that his new brother would be made welcome when the war ended. One more Carter was just a drop in the bucket to the extensive Carter clan. Meanwhile, they had many ancient legends regarding shapeshifters, and the thought that Andrew had become one did not seem to trouble them in the least. Andrew was grateful he could write to them in Sioux to avoid attention from the censors.

Burkhalter never said another word about the experiment after he awoke from the sedative. He swore Klink to silence on the matter and left the Stalag in an ill temper. That temper was only made worse when Bockstein's lab and all his research was destroyed. Hogan's men had freed the lab mice and the hapless human subjects first, of course, getting the humans out of Germany. Bockstein, meanwhile, ended up in Switzerland, where he got a job in the Zurich zoo and never did another scientific experiment again.

The End