Sir Handel Helps Zak & Jimmy is a Potential Plotlines episode.
Sir Handel warns Zak and Jimmy about a broken viaduct, but Zak and Jimmy don't listen to his advice and colllect some slate trucks from the incline and take them to Great Laketon. But the trucks have a plan and push Zak and Jimmy into the broken viaduct. Sir Handel collects Greg the Crane and rescues Zak and Jimmy. Mr Percival scolds Zak and Jimmy while Sir Handel is a really useful engine.