Superman Vol 2 #050 - CGC 9.2

Clark Kent tries to get used to ordinary life, using public transport, going through the day-to-day struggles, and watching Gangbuster and Guardian protect Metropolis without Superman. He goes to the Daily Planet, where the situation is stressful between the staff and Perry White after Jerry's death. Clark takes Lois to have lunch, and he proposes to her to marry him, to which she answers she needs time to think about it with everything that's been going on with her mother's illness. Suddenly, Lex Luthor calls Lois to ask her to write his biography, with Lois rejecting his proposal. Clark takes the phone and tells Luthor he has the Krimson Kryptonite and will give it to him if he gets a story in exchange.

Clark goes to LexCorp with the Krimson Kryptonite and Lex takes it from him. But before kicking him from the building, Lex tells the reporter that the Kryptonite was given to him by Mister Mxyzptlk. But Luthor doesn't realize that he is violating the rule he had with Mr. Mxyzptlk: not telling Superman the truth behind their scheme. Thus Superman gets his powers back.

Mr. Mxyzptlk appears and reproaches Luthor for breaking their rule. The Imp confesses his scheme to Superman and tells him that if he punches Luthor, he'll leave their dimension. Superman refuses and flies away, but Mxyz transforms into a big creature made from a bit of Lex's skin, so Superman punches him, and the Imp returns to his dimension.

Everything goes back to normal in Metropolis as the word of Superman's return is made public. Clark visits Lois at the hospital, where her mother has recovered from her illness, and he repeats his marriage proposal, and this time Lois says yes.