Of course, they need adult supervision, and the best candidate for that is, somehow, Gene (Mel Gibson), the crotchety, reclusive old neighbor who turns out to also be a retired detective with his own tragic backstory involving a missing child. Gibson plays him with all the gruff and growl he’s gotten used to playing in his later years, which fits him nicely into a reluctant father-and-son beat with Thames, the pair learning both to trust each other and solve the mystery. (Thames makes for a capable lead yet again, even as he’s left with little but to gawk and crack wise.)