What happened to the blue French horn on How I Met Your Mother? The instrument made its debut during the sitcom's pilot episode in 2005. It appeared a few more times throughout the series, serving as a symbol as Ted and Robin's relationship, only to reappear in the series finale.

Ted Mosby and Robin Scherbatsky (Josh Radnor and Cobie Smulders) went on their first date in the How I Met Your Mother premiere episode. They had a memorable dinner at a restaurant called Carmichaels before Robin was called away for work. Before she left, Robin commented on a blue French horn hanging on the wall, saying that she wanted one to display in her apartment. Ted later returned to the restaurant and stole the ornamental horn in an effort to show how much he cared for her. Their relationship didn't work out due to Ted's overzealousness, but Robin kept the horn over her mantle.

Related: How I Met Your Mother Forgot About Robin's Bullfighting: Here's What Happened

Later in How I Met Your Mother season 1, Ted tried to win back Robin. He surprised Robin at her apartment with candy, flowers, and a group of musicians with blue instruments, a nod to the blue French horn from the pilot episode. Ted was forced to return the horn in the following season during the episode titled "Something Blue". He and Robin returned to Carmichaels when they were giving their relationship another chance. The restaurant owner recognized Ted as the man who stole the French horn. Ted tried to run away but the owner made Ted return the instrument in order to get his credit card and driver's license back. Prior to giving the horn back, Ted and Robin broke up, leading viewers to believe that the object signified their relationship.

Ted holding out the blue french horn to Robin on How I Met Your Mother

Ted must have stolen the blue French horn a second time considering it was in Robin's possession in How I Met Your Mother season 5. Ted still had feelings for Robin but she planned to leave their shared apartment to move in with her boyfriend Don. In the episode "Twin Beds", Ted came home to find Robin's room empty except for the blue French horn left against the wall.

The French horn made its way back to Carmichaels by How I Met Your Mother season 7. Ted and Robin's on-again-off-again relationship was still a major plot point. Robin recently broke up with her boyfriend so Ted saw it as an opportunity to confess his feelings for her. After picking her up from the airport, Ted took Robin to Carmichaels. The blue French horn was still on the wall but this time around, it was chained up. Ted continued to struggle with his feelings for Robin as mentioned in the season 9 flashback episode "Platonish". While discussing the prospect of winning Robin back, Ted mentioned that he would use the French horn. This plan would come into play well in the future.

When Ted was finished telling his kids the story about how he met their mother, they encouraged their dad to be with Robin since it was so clear he still had feelings for her. In the How I Met Your Mother series finale, Robin heard her doorbell ring in her apartment and when she looked out the window, she found Ted on the street below holding the blue French horn. Robin instantly understood the gesture and the pair ended up together long after their first date in Carmichaels. That would have been the last time Ted had to steal the horn since he and Robin would have kept it in their possession after ending up together.

Next: How I Met Your Mother Almost Ended After Season 8 - Here's Why