Yes, these are worth watching, stand-alone episodes that are just as entertaining as the rest of the series. But WHEN should you watch them? There are 2 episodes in this OVA. The first episode fits in the best between season 1 and 2 IMO, but it can be watched practically anywhere after Sherlock and Watson get introduced. The 2nd episode fits in the best between episodes 6 and 7 in season 2, so if you want to watch them both at the same time then I'd reccomend watching them both between episodes 6 and 7 in season 2. Of all the stand-alone episodes in this whole animeI honestly think these were 2 of the best ones.