Donald Frank Callahan (19 letters) is the "damned" priest who first appeared in the novel 'Salem's Lot. He makes his first appearance in the Dark Tower series in Wolves of the Calla, although his involvement in the series was hinted at in the afterword to Wizard and Glass. After being marked by the vampire Kurt Barlow, and therefore forced out of his church, Father Callahan spends time volunteering in a homeless shelter. Callahan made it a goal to get even with the vampires for what they did to him and his friend, who contracted HIV after being bitten by a vampire. He is aided in this by his ability to spot the vampires; since Jerusalem's Lot (and the forced taking of some of the vampire Barlow's blood) he has been able to recognize vampires at a glance. Like Jake Chambers, Callahan enters Mid-World after dying in his own world, although in Callahan's case the death is his own doing; he jumps from a window to escape agents of the Crimson King, then arrives at the Way Station from the The Gunslinger, shortly after Jake & Roland left it. He becomes a partial member of the ka-tet, assisting the ka-tet in the Battle against the Wolves and Susannah's rescue mission from 1999 New York, and sacrificing himself so that Jake may live in the final stand in The Dark Tower VII against the can-toi (low men) and vampires. For the second time, Callahan kills himself before allowing himself to fall at the hands of the vampires.