When a young, non-verbal boy is found hiding in a stranger's garage, the CSI team searches for his missing mother. Also, Max receives a strange letter with symbols in silver ink that Folsom and Allie recognize from prior crime scenes.

The CSI team investigates the death of an archaeologist found near the breakthrough discovery of an ancient civilization. Also, Max locates another cryptic note written in familiar silver ink after a mentally distressed woman kills her attacker.