Mutant X Belongs to Marvel Studios, Fireworks Entertainment, and Tribune and is a one-shot prequel to my Life With Derek crossover fics set long before Brennan joined Mutant X.

Brennan moaned as a wail pierced the silence. Casey had woken up again. And he had no idea why. Wish Jessica was here, he thought to himself, his thoughts once again going to his girlfriend. However, she wasn't here and he was. With a sigh, he got up and went to the crib he had procured for her.

"What is it, hon? You hungry?" he asked as he gently picked her up. The girl continued to cry and he went to the kitchen and opened the refrigerator to grab one of her bottles. However, instead of quieting at the sight of her bottle as was her custom, the cries only grew louder. Okay, not hungry, he realized and quickly checked her diaper. Dry. Okay, so it wasn't hunger or need of a change. What was he supposed to do? He wasn't a father. He had no idea what he was supposed to do here. Almost desperately, he began walking back and forth, gently rocking her. Maybe a song of some sort. A lullaby or something, he thought to himself. Well, here went nothing.

Hush little Casey, don't say a word.

Papa's gonna steal you a mockingbird.

It can whistle and it can sing, and it can

Do most anything.

But if that mockingbird won't sing,

Papa's gonna steal you a diamond ring.

Okay, so it wasn't exactly traditional, but it was working.

And if that diamond ring turns brass,

Papa's gonna steal you a looking glass.

And if that looking glass gets broke,

Papa's gonna steal you a Billy-goat.

And if that Billy-goat won't pull,

Papa's gonna steal you a cart and bull

As Brennan sang, Casey's screaming lessened until they were whimpers.

And if that cart and bull tip over,

Papa's gonna steal you a dog named Rover.

And if that dog named Rover won't bark,

Papa's gonna steal you a horse and cart.

And if that horse and cart break down,

You'll still be the prettiest little daughter in


Casey whimpered again and snuggled close to Brennan.

"Ah, I see. You just wanted some Daddy time," he said fondly. "Well, no need to scream to get it, Case. You'll always have me," he promised. And that was one promise he intended to keep, no matter what.