For those who don't remember, this is the episode that features Denis Parker, a man suffering from amnesia for seven years after taking off with £800 of his employer's money. All through the episode, we are led to believe that Dennis was innocent of the crime and his amnesia was the result of him being kidnapped and thrown out of the car by the real thieves.

But then...

At the end of the episode, we see Kate and Nick in bed together reminiscing on how they'd 'kept an innocent man from prison' and Nick suggests that the mystery of Dennis Parker will be forever unsolved. They both fall asleep and immediately Nick has a flashback to 1958, the yearof the crime.

The ending has always left me a bit puzzled. We see Dennis sitting in the front seat of the car laughing and joking with the two other men in it and the episode ends with Nick bolting awake. I have always believed that this short scene illustrates that Dennis has been lying to everyone for seven years and is in fact guilty, although now he will never be brought to justice under the Double Jeopardy Act which was still in place back then. Or was the whole scene just a figment of Nick's imagination and him thinking what would things have been like if Dennis was in fact guilty? What do you think? Me, I will always go for the first option, although how Nick knows what the other two conspirators looked like is anyone's guess.

My interpretation is that Nick suddenly worked out what, in all probability, actually happened, and that Dennis is guilty.