A few of the apostles go night fishing at Tiberias. They don't catch anything and return to shore, where Jesus is waiting. He asks if they have any fish. No, they reply. He tells them to cast their nets off the right side of the boat, and they come back so full they can't haul them up. One of the disciples comments to Peter that this must be Jesus doing. For some reason, Peter is naked, and for some even more bizarre reason, he puts his clothes on and jumps into the sea. Fortunately, the others are more sensible and row the boat the hundred yards or so back to shore, towing the net full of fish.
When they arrive, they discover that Jesus has set up a fish fry. He asks them to add their catch to the picnic, and it turns out they caught 153 fish. All of them are so convinced by now that this really is Jesus that they don't ask him for ID or demand to poke his injuries or anything.
During the picnic, Jesus keeps asking Simon Peter if he loves him more than he loves anyone else, and Simon Peter keeps affirming that he does, and Jesus keeps telling him to feed his sheep. After asking him three times, Jesus changes the subject and informs him that when he's old, he'll be crucified as well.
As they've been talking, another disciple has approached. Simon Peter asks what his fate will be. Jesus says it's not really his business, but this one will probably survive until he returns again. I'm not going to go back and re-read this entire book, but I think this is one of the few, extremely muted, references to the apocalypse in this book. Funny how things change when it's a hundred years later and your prophecies haven't come true.
Anyway, the other disciples falsely conclude that Jesus means that particular apostle will not die, but the book is at pains to point out that isn't true. The book also says that there are so many other things Jesus did that if they were written down, the resulting library would be bigger than the whole world.