The afternoon before, when he visited my room, he seemed mosly normal, and he ate some food and drank some water. That might've been the last time he ate anything. The following morning he was really sick and by the time the vet arrived he was just sitting on the closet floor shivering a little, unable to walk.
Almost as soon as the vet saw him, he said "he's in really bad shape". He weighed him (under 8 pounds, down from around 12), smelled his breath, took a blood sample, and diagnosed him with kidney failure. Until he said "this is a dying cat" I thought it would be okay :/
I went to my room to Google directions to Angell Memorial animal hospital, and by the time I got back to the kitchen, he was dead.
He's been known by many names over his lifetime, among them: You, That Other One, Testicules, Oily, Rosencrantz, Prince, black fluffball, and the Princeling ("You" and "That Other One" due to the fact that he looked so much like his sister that Rowan took a while to learn to tell them apart). Not very smart, but fortunately he left the brain cell for his sister (they shared it). His favorite pastimes were bellyrubs, sitting on paper, licking plastic bags, and liberating pasta. Now that I think of it, I haven't seen him licking plastic bags for a long time, maybe that was a warning sign. Cats are so subtle about their ailments.