During their first meeting in the Pilot, Jack tells Kate the story of how he counted to five to prevent himself from panicking in a surgery. He later asks her to retell this story to prove that the Others have freed her and Sawyer, and Kate repeats the story in an emotionally charged scene in Not In Portland.

Kate uses Jack's "count to five" technique at the end of the first episode when being pursed by the smoke monster. She uses it again when climbing down into the hatch.

Kate sews up Jack's wound when she meets him in the Pilot. Jack references this in Something Nice Back Home, stating that it wouldn't be the first time that Kate acted as a nurse for him. She references also this in The Incident while wiping blood from his face, asking him "do you remember when I stitched you up?". Jack stitches up Kate's gunshot wound in What They Died For. He references their first meeting in The End by saying "I'll be fine. Just find me some thread and I can count to five".

In White Rabbit, Jack tells the survivors that they can either "live together" or "die alone". Kate quotes this back to him in Man Of Science, Man Of Faith. She also quotes this to Sawyer in Every Man For Himself.

Kate flirts with Jack while he plays golf in Solitary. She again flirts with him while they are playing golf in Collision.

Jack and Kate have two scenes involving a shower. Jack walks in on Kate while leaving the shower in Everybody Hates Hugo, and they are shown kissing in the shower in a flashforward in Something Nice Back Home, a scene which finally reveals that their off-island relationship.

They also have two scenes set in a hallway. Kate apologises to Jack then helps him walk out in Left Behind. They kiss in a hallway in Something Nice Back Home before Jack carries her to the bedroom.

Kate initially refuses to leave Jack behind in I Do, saying "I can't leave without you! Jack, I can't! I can't!", and later she returns to save him. Jack refuses to leave Kate behind on the freighter in There's No Place Like Home. Kate again wants to turn back for Jack after he jumps off the ship in The Last Recruit.

Jack tells Kate that he loves her in the season 3 finale Through The Looking Glass. Kate tells Jack that she loves him and he replies that he loves her too in the season 6 finale The End.

Kate is imprisoned in a cage by the Others during the first episodes of season 3. Jack bargains for her freedom in exchange for operating on Ben. He again frees her from the same cage in The Candidate.

Jack carries Kate after she is stunned by the Others in Live Together, Die Alone. He again carries her after she has been shot by Widmore's people in The Candidate.

Jack watches Kate in Sun's garden in Hearts & Minds. Kate watches Jack in the river in The End.

Kate helps Jack to walk when injured or hurt in Left Behind, Something Nice Back Home and The End.

There is a recurring theme of running throughout the series. When Jack and Kate first meet and he tells her the count to five story, she comments that she would have run for the hills in that scenario. He replies "you're not running now". He later tells her to run if she hears anything while out in the jungle. In I Do, Jack shouts at her "Kate, damn it, run!".