Hank McCoy, The Beast

"I'll need a sample of the amniotic fluid," the blue-furred beast said, flashing a mouthful of fangs. Sue Storm winced as he pressed the needle against the small swell of her abdomen. Even with a local anesthetic, she winced as it pierced the skin, the muscle beneath, and then the wall of the uterus. His deft fingers carefully drew a small amount of almost-clear liquid, then removed the needle, stopping the blood with a bit of cotton and a band-aid.

The Invisible Woman sat nervously on the medical examination table in the rebuilt X-Mansion's health clinic, dressed in nothing but a maternity bra and her pants. The old building had been destroyed and rebuilt so many times; she had been completely lost when Doctor Hank McCoy, AKA The Beast, had guided her through the labyrinth of corridors for her discreet prenatal check-up. Reed had wanted to be there, but Blastaar had somehow invaded the Microverse, and Reed was helping Hank Pym and the Guardians of the Galaxy deal with the situation.

The Beast whistled to himself as he fed the sample into a complex-looking machine. He was short, broad, hugely muscled, but it was the blue fur that always caught and held Sue Storm's attention. It was the exact consistency of a huge tabby cat. She had to fight the urge to rub his belly and chuckle his chin. Despite his fierce appearance, he was also a genius in genetics and biochemistry, and had a good bedside manner.

Until the test results came back.

"Oh my stars and garters," the Beast said.

"What is it?" Sue said, suddenly anxious. "Is there something wrong with the baby!?"

"The fetus is in perfect health," McCoy said after a moment. "I can prescribe you a supplement to deal with the nausea, and help ease the interaction between the mutant and non-mutant cells. However, the genetic analysis of the stem cells is...I don't know how to put this delicately. What genealogists call a 'non-paternity event.'"

Sue Storm's brow furrowed.

"Hank, what are you saying?" she said.

He looked at her strangely, then tapped some screens. On the screen nearest Sue, three genetic sequences hovered. One was labeled Richards, Reed. The other was labeled Richards, Sue. The third was labeled Mutant Fetus. Colored lines were drawn between segments of Sue and the baby's DNA. But none from Reed.

"The sperm donor is not Reed Richards."

"How is that possible!?" Sue said, suddenly tense. "I haven't been with anyone! I wouldn't cheat on Reed. I—Oh, God, was it a Skrull?"

"Not a Skrull. Though that's the curious thing," the Beast said, tapping more things. Some of the screens were at the level that he could raise his foot and use prehensile toes to manipulate them. "The paternal genetics aren't in our records, and we have records of nearly every mutant on Earth. What's more, the X-gene complex isn't typical of any mutants in this dimension."

Glowing bits of the fetus' DNA were highlighted.

"Because of tens of thousands of years of persecution, many mutations exist in known lineages. A bottleneck effect. All of the feral mutants like Wolverine and Sabertooth share common ancestors. This X-gene complex, however, is not in any of our records. It doesn't share a common ancestor with any known mutant on the planet today. That suggests the true parent is a mutant from another world or dimension," the Beast said.

Sue held her head in her hands in shock. Reed wasn't the father of her baby. Then who was?

"How?" she asked. "How did I get pregnant by some mutant I don't even know?"

"We'll have to ask," the Beast said. "When we find him. With the partial DNA sample we have, Cerebro should be able to locate them. Then, perhaps, we'll get some answers."