Q follows Vash to the station and stirs up trouble.
Dax brings back Vash, the archaeologist O'Brien knew from the Enterprise, from the Gamma Quadrant, and Q arrives with her. Vash wants nothing to do with him, and Q needles Bashir and Sisko, who ends up flooring him in a boxing match Q conjured. Meanwhile the station suffers growing power drains.
Quark arranges an auction of Vash's finds, including a valuable crystal. The drains worsen until the station is being pulled toward the wormhole, and the crystal is revealed to be a living being that has been feeding on energy. Once it is released it leaves, and the station is saved.