When a body is discovered holding a 300-year-old finger, Booth and Brennan are lead to a dive site near Assateague Island where pirate treasure may be hidden. Hodgins is able to leave the lab and participates a dive that locates more remains, some of which were stolen from the Jeffersonian's collection. However, when Hodgins volunteers for another dive, Booth and Brennan must race to save his life when they identify the killer.