Gerry is a older gentleman, an author in his retirement years, who challenges random people in the park to games of chess. He is eccentric, but something seems off about him to people beyond that, and not in any way they can put a finger on. The protagonist, Emma, is a fan of his books. He is also a teaser character partially, for what is to come.

He is modeled off of Peter Capaldi's interpretation of the 12th Doctor (Doctor Who) and is a teaser character. I don't want to copy that directly obviously, but it's an idea of what direction to take, I suppose.