A few years ago a did a presentation / thought piece at Creative Scotland's Media Literacy Conference on Multimodal Learning. At the end of my input I demonstrated (amongst other things) YouTubes capacity to be interactive and to link to other YouTube Videos during or at the end of a video. It was a fairly new feature at the time (back in 2011) and I suggested that it might be nice for schools to use the feature to create some interactive storytelling or multimodal mysteries.
I still think there is a lot of potential for this but I was reminded of it recently when I saw Canadian Herritage's project titled 'Journey Into the Arctic'.
Journey Into the Arctic is an adventure (set in YouTube) in which you play an explorer on a mission to find the Northwest Passage. Just like a classic mystery book you have to make decisions at the end of each short video (chapter) on how the story unfolds and to help you reach your final goal.
Lots of potential with this - not just as an education resource in its own right but also as an inspiration to create your own YouTube multimodal mysteries stories.