Kalahari

Four months after her mother's death, Sarah is living on her father's African safari camp when he agrees to host an educational trip for five American teenagers in exchange for badly needed funding. Soon after the group arrives, Sarah's father disappears into the Kalahari Desert, leaving her to guide the visitors and search for him with no adult support.

The desert turns out to hold worse than heat and distance: a lion attacks the group, its coat shimmering an unnatural silver. Sarah and the others discover the sheen comes from a virus that's rewriting the animals it infects, and that finding her father may mean confronting the source of the outbreak directly.

Kalahari is the third book in Jessica Khoury's Corpus trilogy, following Origin and Vitro. Like its predecessors, it's a standalone story sharing the same speculative-biology premise rather than a direct sequel.