![Backfire](https://image.tmdb.org/t/p/w500/k5PhYyvsqSq42q4ixfFJA6VkkTu.jpg)
Mark investigates an old case as part of his coursework research, and uncovers an apparent miscarriage of justice which implicates Ed in a fit up. The pair investigate the case to try to work out what really happened, and discover that the truth is not necessarily what it appears to be.