Offred believes in several different fates for Luke. First she imagines Luke as a corpse lying in the forest, and hopes he had a quick death from a bullet. Then she imagines him alive in prison, worn down and old-looking, with a gash as red as tulips on his face. Finally she imagines him safely over the border, making contact with a Resistance movement. She imagines that Luke might find a way to send her a message and rescue her and their daughter. Offred keeps believes in all three possibilities for Luke at once, or else she feels that she can’t believe in anything.
Though Offred has previously said that she prefers not to hope (for example, in Chapter 12, when she thinks about her daughter), this passage shows her being both hopeful and maybe willfully blind. She misses out on one big possibility—maybe Luke is now working for Gilead. But Offred would prefer to idealize Luke, and maintain her love for him as a form of escapism.