The True Lifesaver is a comic made by Thunderhawk03 of deviantART. It is an alternate ending of the episode Spike at Your Service.
It starts a while after Applejack saves Spike, she refuses to take Spike's offer to help her with stuff. Spike pleads her to do so since it's part of the Dragon Code, but Applejack says that Spike already owes that to someone else. She reminds him of somepony who looked after him and was always there for him, and that he can call that pony not just a family, but also home. Spike figures out it's Twilight Sparkle Applejack is talking about and decides that she's right and goes to talk with Twilight.
Spike goes to Twilight's house and asks her if she has a minute. Twilight says she does and asks what Spike has to say. But before Spike could talk, he begins to cry as he runs over to Twilight and hugs her. Twilight asks what's wrong, but Spike says he's so glad he has her. Twilight is tearfully touched, as she and Spike both hug each other.