Starts as Sherlock's plane is taking off at the end of His Last Vow. When he finds out that Moriarty is alive and that he's being recalled from his mission, Sherlock decides that he should have told John how he felt before he left. So he walks off the plane and kisses him.
"The breakdown: 35. Canuckian. ESL professor. Choir conductor. Former/now part-time classical singer. Writer. Extreme Geek. Diehard Johnlock shipper. Not a fan of Mary, at all. Firm believer that Mary needs to face justice for her many crimes and to do it elsewhere, and the sooner her departure comes, the better."
Another good Season 3 "fix it" fic from SilentAuror, this one starts from the very end of "His Last Vow". Sherlock reveals his feelings for John after he gets off the plane and the rest is everyone trying to deal with that and with Mary. Johnlock.