Place one atop Tribble side deck during the seed phase.
Side deck is now open and in play. Once each turn, you
may draw up to 3 cards from side deck, then play or
discard each.
OR
Stock in deck and play (once each turn)
to download from your Tribble side deck one Trouble or
Tribble card , or to nullify any card that is closing another
Storage Compartment Door; then discard doorway.