S2, E10: All seems lost with firehouse 51 on the verge of closing its' doors, thanks in no small part to Gail McLeod (guest star Michelle Forbes), but Chief Boden (Eamonn Walker) and the rest of the house refuse to allow themselves to sit by and let it happen. An emergency call to an apartment structure fire tests everyone's limits and puts the squad in harm's way. Meanwhile, Dawson (Monica Raymund) receives some life-changing news and union president Greg Sullivan (guest star Eric Slater) makes headlines, which has an immediate impact on Mouch (Christian Stolte).