Gabriel Weston investigates the forensic advances that have elevated the murder weapon from its role of mere evidence to that of key witness.
Cat and Vincent take their relationship to a couples counselor when Cat dives into her work and suspects a wealthy transplant recipient of being involved with the mysterious experiments on innocent people in the city.
The Ninja hear of another way to learn Airjitzu - from the ghost of Sensei Yang at his haunted temple - but there's a warning if you are trapped in it by sunrise, you will become a ghost, too. Meanwhile, doubting she's a Water Ninja, Nya quits her training to take Ronan to her Samurai X cave...but has a run in with Moro.
Ethan finds a bomb planted in his car, which leads him to question people he thought he could trust Kate and Harold discuss their fertility issues with Nurse Pam Ben's relationship with Amy heats up.
After only a short time in the wild, the men find that extreme isolation is beginning to take its toll. A survivalist undertakes a massive cabin project, one man loses his most important tool and another is charged by a large predator leaving him to fend for his life.
Marc's novelist pal asks him to guest lecture at the college where he teaches, but their friendship is tested when sparks fly between Marc and the TA.
Cutler gets a surprise visitor. Hodiak and Shafe work the murder of a Hollywood star. Charlie goes gun shopping.
There's more creeping around Fort Paull as the team face some menacing mannequins. But what awaits them in the tunnels
Gretchen makes expensive arrangements to hide Antoine in order to prevent Bridget from learning that John illegally transferred him to the surgical center. That means John needs to ask the gang for money, however. In other events, a past indiscretion tests John's relationship with Samantha.
The Titans are having a terrible time on their camping trip, so Robin suggests that they each tell a scary campfire story.
Hoff hopes to become a UN Ambassador so that he can embrace his potential.
Scott gets ready for his launch and Rene gets the chance to tell her story in a magazine interview.
A man needs to clean up his three-acre hoard whilst a woman hoards to try and get over the death of her son.
An RV trip to the Mud Bog Raven goes four-wheeling Karynda and Ashton mud wrestle Duke is caught between two girls Hunter and Kelsie make a decision about their relationship.
When Lily is upset to realise Matt is going out with cool girl Greta Masters, Jas plans a make-over slumber party to cheer her up.
Morgan gets stuck in the grips of an ice desert with no shelter in sight Marty's return to Alaska's Revelation Mountains takes an unexpected turn.
Joss moves too quickly in her new relationship with Harry. Karen and Vivian grow closer. April gets some parenting lessons on a camping trip. Calista finally sees Luca's true motives.
The public get to vote for their favorite islander and the boy and girl with the least votes will have to leave the island.