Thomas, Percy and Old Slowcoach is the sixteenth episode ever made in Season 5.
Thomas and Percy discover and old slow coach in the scrap yard. She looks very dirty, but is in perfect shape so they try to help her. Meanwhile, James runs into trouble when his fuel tankers catch on fire. The fire fighters soon help him by putting out the fire. Later that day, there is another fire at the workmen's hut close to where Thomas and Percy were taking on water. Unfortunately, the fireman discover that they ran out of water after putting out James' fire. Thomas suggests that they use the water from his and Percy's tanks. The plan works well and the fire was soon put out, but the workmen's hut is destroyed. Percy comes up with the idea of using Old Slow Coach as the workmen's new hut. So after being cleaned up, she happily enjoys her new life.
- The new station at Tidmouth Hault now appears to be a shed.