The growths had to be part of a tumor. Yaya had read about them popping up without warning, twisting all manner of wayward organic matter inside. Ruby must have thought tumors, too, or she would’ve answered Yaya at the clinic.

Cells were doing things they shouldn’t in places they had no business being. In that way, tumors and Sibs didn’t sound too different.

Thirty-two years ago, there was no such thing as Sibs. Yaya wasn’t conceived yet, Nancy Reagan had just won the ’88 election, and when you heard the word chimera, you thought of a mythical monster drawn by an overeager, animal-loving five-year-old. But then AlphaBeta Pharmaceutical cracked INZ9-00’s eggshell.

Nihilistic pundits suggested it was a cure for overpopulation that backfired, while religious figures alleged ABP had tried a good old-fashioned tampering in God’s domain.

Not like anyone could ever be certain of ABP’s genuine goal. For all Yaya knew, some corporate Frankenstein had stirred up random organic code and then released it just to see what would happen. In some cases, the later-named double-zero virus caused sterility. In others, tumors. More frequently, the virus conjured up a weird form of super-fertility, so much that Yaya once wondered if the virus’s true purpose was to create more ABP customers. Twins, triplets—

those made sense.

Most often, though, the kids formed genetic chimeras.

The way Yaya understood, a chimera like her happened when Zygote A partially consumed Zygote B. She should’ve had a twin. Instead, still-growing Yaya had slurped up her sibling. Now she wore two sets of DNA, divvied up between different organs.

A condition that ABP could claim to own when facing Congress later. Their higher-ups underwent investigation for the virus, but consequences came in short supply back then. Because their virus had caused developmental differences in offspring, they argued successfully to co-ownership IP rights to chimeras’ DNA sequence.

This might have meant nothing if not for Sibs.

If a chimera formed when Zygote A partially consumed Zygote B, then Sibs was the result when Zygote B bit back. The DNA strands demanded each

become their own person, but Sibs never struck before puberty, and by then no chimera remained in the womb. Without enough genetic material, chimeras’

bodies tore themselves apart, donor organ rejection on a systemic scale.

No corporate entity wanted to dole out free healthcare, but because of the IP arrangement, the situation offered company terms that even AlphaBeta Pharmaceutical understood—you break it, you bought it.

From puberty onward, every chimera submitted to monthly mandatory Sibs checkups.

Yaya couldn’t see the point. In all these years, ABP hadn’t found a cure.

That didn’t stop her from going every month, free checkup being free, and Jumpies didn’t exactly provide healthcare benefits. Checkups promised she didn’t have an STD when she and Starts-With-D had slipped under the sheets.

But along with taking weight, height, and blood, ABP doctors gave injections at every visit. An immune system booster here, a suppressor there, antibiotics galore. She never asked questions, but now she wished she had. What are you putting inside me? Doubtful they would have answered in any helpful way.