Agent Six of Hearts Books in Order

Genetically engineered agent Six of Hearts works for vigilantes while concealing his origins in a secret laboratory. When his team investigates his creators, a meeting with another boy sharing his DNA threatens the life he has built.

Suspected of betrayal by his own agency, teenage operative Six must work alone while searching for his kidnapped twin. A dangerous girl shadows him, and every potential ally may be another threat in the hunt for his brother.

Revived four years after his death, Agent Six discovers a city ruled by secret police and a killer targeting his friends. To survive again, he must investigate his own murder while confronting enemies who refuse to stay dead.

A physicist sends Agent Six backwards through time, leaving him one chance to prevent a catastrophe by destroying her machine's components. Teenage thief Ashley Arthur may help him reach them, but her own agenda complicates their alliance.