(CNN) -- The latest suspense and mystery in writer Dennis Lehane's life isn't his new novel, but a missing beagle named Tessa, and he'll name a character in his next book after whoever gets her home, he said in a recent Facebook post.
Tessa, a rescue dog, went missing from the author's home in Massachusetts on Christmas Eve. She is microchipped but was not wearing identification tags, he said.
Lehane and his family were in Florida over the Christmas holiday. Someone was watching Tessa, but a gate was left open and she wandered out, he said.
As of Friday, the post had garnered 32,500 likes, 225 comments and 330 shares on Facebook, in addition to mentions on various blogs and websites.
"I'm kind of overwhelmed by social media," the writer said Friday on CNN's "Starting Point." "I never even understood the impact of social media until I did this. I just put up a little note on my Facebook page and just said if anybody gets information that leads to her coming home, instead of putting up a reward, I'll put up something a little different -- I'll name a character in a book after you."
The author of "Gone, Baby, Gone," "Mystic River" and "Shutter Island" says he's named characters after real people for charity in previous novels, such as 2012's "Live by Night," when he used a real name for a state police officer.
His upcoming novel is set in the 1930s, he said, so if the name of the person who finds the dog doesn't "fit in the 1930s," he will use the name in a story with a more modern setting. There is no guarantee what kind of character the rescuer will be in the novel, but "I would never make you somebody truly awful," he said.
Lehane said there have been reports of Tessa spottings in the Brookline and Allston areas around Boston, but they seem to be false leads.
"She's super fast, she's very, very sweet, but she's also wary," he said, "She's skittish, so definitely don't chase her. If you see her, just contact any of the numbers or websites, and we will get the proper authorities out to find her."