Taumoeba contamination of fuel

Grace discovers that the Taumoeba-80 strain has evolved the ability to penetrate xenonite, the alien material used for Rocky's ship and the breeder tanks. The Taumoeba escape their containers and infest the Hail Mary's fuel supply, consuming all the Astrophage and leaving the ship dead in space. This catastrophic event threatens to end the mission, as the ship loses all power and propulsion. Grace is forced to improvise, using the beetle probes as makeshift engines and eventually deciding to rescue Rocky, whose ship has suffered the same fate.