it's all lies, darling (Thiam- Canon Divergence AU Fan Fiction)

"Where's your pack?"

This time, Theo winces. The boy's voice is soft and somehow sweet and exhausted just like his scent and Theo huffs.

Theo's pack is dead. Josh's throat ripped, Tracy's guts out. Corey and Hayden nowhere to be found. The girl was probably smarter than Theo and left the city without second thought. The chameleon disappeared as Theo taught him to, but Theo is pretty sure that he is still around, spending his time and freedom with his human boy. But his pack is long gone, their blood behind Theo's nails.

The boy notices his reaction and gives him an apologetic grimace.

"You don't have one. Sorry."
...
Or, the one where Liam is bit after Monroe leaves the town and acidentally falls in love with his pack's number one enemy.