Archimago (because it was he, masked as the pilgrim, in case you haven’t guessed), follows Una, hoping to kill her. But the rest of her adventures as well as the result of Satyrane’s duel, Spenser announces, will be told in another place, thus ending Canto 6. He in fact never got round to writing about the results of the duel, although Satyrane reappears in Book 3, so I guess he survived.
Meanwhile, in another part of the imaginary land, Duessa catches up with Redcrosse, who is sitting tired in a green grove near a fountain, with his armours off. She remonstrates a little bit with him about leaving her behind, but making sure it’s mixed with sweet words, i.e. she doesn’t want to come across as a nagging bitch. After all is forgiven, they engage in what I understand from Spenser’s euphemisms to be sex, or at least heavy petting: “Yet goodly court he still made to his Dame/Pourd out in loosnesse [lewdness] on the grassy ground/Both carelesse of his health and of his fame” (Book I Canto 7 ll. 55 – 57). Kids, having sex on the cold grass can be dangerous, what with urinary infections and so on. But even more dangerous is the fact that the fountain, from which the knight drank, belongs to a nymph who was cursed by Diana when she got tired and sat down in the middle of the hunt. Diana’s curse gave the water of the fountain of which the nymph was in charge, the power to turn anybody who drinks it dull and slow. Redcrosse doesn’t feel it yet, but soon he is going to regret it, as they hear a dreadful noise and before he manages to put on his armour, a dreadful giant as big as three men steps out into the glade.