Photo: Bleecker Street In Harry Macqueen’s quiet road trip drama Supernova, grief is not something that begins with death or even significant loss. For Tusker (Stanley Tucci), a writer living with an accelerated form of dementia, early signs of grief occur in the passenger’s seat of an old RV during a trip through rural England with his longtime partner, Sam (Colin Firth). At first glance, the scene isn’t especially revelatory—Tusker and Sam lightly debate the virtues of regular maps over satellite navigational systems and squabble over Sam’s slower-than-strictly-necessary driving, just like any settled couple would.