With the title of this episode being "something old" and the next episode being titled "something new" I expected a double header focusing on the wedding of Barney and Robin, but I guess I'm wrong.
Plot In A Paragraph: Robin Scherbatsky Sr. is in town. He and Barney (the son he never had) bond doing one of Barney's favourite activities, laser tag. But not all is harmonious between the father/son duo, and soon they are at war. Literally. However their bonding time leaves Robin time to carry out an important task, namely finding the locket she buried near the Central Park carousel when she was a teenager, that locket which was always intended to be her "something old" at her wedding. Meanwhile, Marshall and Lily are having trouble trying to decide what to take with them to Italy and what to throw away, so they call in the packing expert, Ted.
So Ted clearly still has feelings for Robin (who didn't know, or at least suspect that??) and Robin is having doubts about marrying Barney, and is maybe thinking Ted is the guy for her. I didn't like the end scene at all!! Everything was fine with Robin and Barney at the end of the last episode, so why bring all this negativity and doubts in to it?? On the plus side Barney and Robins Dad at Laser Tag was great fun.