Bad Radio by Michael Langlois
Sixty years ago Abe Griffin saved the world and gained eternal youth.
Or so he thought.
Now, a man that Abe believed to be long dead is killing the surviving members of Abe's old squad in order to reclaim the relics that they have kept hidden for decades.
The relics form an ancient beacon that must never be used, in a ritual that must never be completed. But the end of the world requires more than just activating the beacon.
It requires Abe.
With help from the granddaughter of his oldest friend, Abe must learn the truth about his immortal body, while at the same time trying to stop a horrifying series of supernatural opponents from sweeping away everything that he cares about.