Simon and Eugene discuss why you can’t go back in time to before you went back in time, the possibilities for using a time machine for committing crimes rather than solving them, and the messages hidden in Crime Traveller, which prove the whole thing takes place in an alternate reality.

Episode Synopsis

Professor Hayward is found dead, murdered in his bathtub.

Slade and Turner are on a date, having just seen a 50-year-old French film.  Turner thinks it’s a timeless classic; Slade, not so much. It has special significance for Turner; it’s the same film she went to on her very first date.  Slade hasn’t got much time to be nosy and/or jealous when Professor Chapman calls out to Turner but is run down in a hit-and-run.  Chapman desperately tries to tell Tuner something but can only point to her wrist before he dies.  For the first time in the series, Slade fails to get the license plate number of the car.

Turner immediately tries using the time machine to find out what happened, but in this case, it only takes them back 3 minutes.  Just long enough for them to return to the present, and then the single most expensive piece of equipment, the crystal, breaks.  Without £20,000, the time machine is never working again.

It turns out that both professors Chapman and Hayward worked for Web Biotech, and although Turner has never met either of them, both were known names to her as they worked in her father’s field.  She is assigned to work with Slade as he investigates their place of employment.

They meet with the Technical Director, Steven Marlow, who, to no surprise to anyone that’s ever watched a movie or TV show, is the very same man with whom Turner went on her first date and was her boyfriend. Turner’s father previously tutored him. 

Slade immediately suspects he’s involved in the murders, and it’s not at all because he’s jealous.

Marlow takes them to meet Sebastian Webb, owner of the company, and he is none-too-complimentary about Hayward and Chapman’s work, which has overrun budgets and produced nothing. He strongly indicates that he thinks they, and perhaps Marlow, were up to something.

In their lab, Slade notices and is curious about a locked room, but he’s assured it’s just a generator and storage.

Turner is unhappy about Slade’s attitude to Marlow, and Slade asks if he knows about her father’s time machine.  She assures him that he doesn’t.  More inquiries reveal that Hayward and Marlow were anxious before their deaths – like they knew something.

Slade, ever more suspicious and not-at-all jealous, intrudes on Turner and Marlow having a date. He makes it clear that Marlow is his suspect.

Later, Slade receives a call from an anonymous caller claiming to have information about the murders.  A meeting is arranged, but it is a trap, as an unidentified assailant wearing a hat to conceal his curly hair takes a couple of shots at Slade.  Slade shoots him in the shoulder, but he escapes in the very car that ran down Chapman.

That’s enough evidence for Slade, and he convinces Grissom to bring in Marlow for questioning.

Slade’s case against him falls apart rapidly; first, it’s discovered that he hasn’t been shot in the shoulder.  This is followed by the verification of two iron-clad, if somewhat absurdly coincidental, alibis for the nights of the two murders.  Finally, the nail in the coffin of Slade’s case gets hammered in when it’s revealed that Marlow was with Turner when Slade was attacked.

Marlow is released and promises to sue.  Marlow has been trying to get Turner to work for him, and Slade’s actions mortify Turner.  She decides to accept his offer and show him the time machine.  Police officer Frank overhears that they’re going to Turner’s flat.

When she shows him the time machine, he figures out what it is and kisses her inappropriately.  They can change history with this!

Morris mentions to Slade that his car electronics went wonky outside Webb Biotech during his surveillance, and Slade puts it all together.  There’s a time machine in operation at Webb Biotech. 

He tries to track down Holly, but Marlow has already taken her away, ostensibly to go to a Webb Biotech facility to replace the broken crystal, but later, he holds her at gunpoint.  He intends to kill her, then will use the time machine to create another iron-clad alibi.

Slade breaks into the locked room in Chapman and Hayward’s lab, and it turns out to be a DJ’s sound machine AND time machine and is considerably more hi-tech than Turner’s.  Nonetheless, Slade manages to go back in time two hours and tails Marlow and Holly.  He rescues her from being flash-frozen but only has 12 minutes to return to the time machine.

When they arrive, Marlow is waiting with a gun, preventing Slade from returning.  It looks like it will be Jeff Slade and the Loop of Infinity, after all.

Egomaniac that he is, Marlow tries to convince Turner to side with him, and she does, but only to get the jump on him, allowing Slade to enter the time machine, but not before a stray gunshot starts a fire inside it.  Slade “returns,” and Marlow, not understanding the laws of time, tries to use the machine to go back and prevent the machine from being damaged.  He disappears into… the Loop of Infinity?

Jeff rushes into the burning machine to liberate a crystal of the type Turner needs to repair her time machine, but he holds out on her until she agrees to use the machine to fight crime.