The Death I Gave Him by Em X. Liu

A Twenty-First Century Hamlet.
Hayden Lichfield's life is ripped apart when he finds his father murdered in their lab, and the camera logs erased. The killer can only have been after one thing: the Sisyphus Formula the two of them developed together, which might one day reverse death itself. Hoping to lure the killer into the open, Hayden steals the research. In the process, he uncovers a recording his father made in the days before his death, and a dying wish: Avenge me...
With the lab on lockdown, Hayden is trapped with four other people—his uncle Charles, lab technician Gabriel Rasmussen, research intern Felicia Xia and their head of security, Felicia's father Paul—one of whom must be the killer. His only sure ally is the lab's resident artificial intelligence, Horatio, who has been his dear friend and companion since its creation. With his world collapsing, Hayden must navigate the building's secrets, uncover his father's lies, and push the boundaries of sanity in the pursuit of revenge.