The fourth season finds Mike starting a new career as an investment banker. However, he soon finds himself in an awkward situation when a takeover battle pits him against businessman Logan Sanders and Harvey, who represents Logan and his company. The fight is complicated by Mike's personal animosity toward Sanders, who once had an affair with Rachel; and, later, when the SEC investigates Mike and Harvey for possible collusion. On top of all that, Mike and Rachel's relationship hits a rough patch. In other events, Louis enters into a shady deal with financier Charles Forstman; Donna faces serious legal problems; and Jessica navigates tricky issues with on-again, off-again lover Jeff Malone.