automatic layers?

I need layers to appear automatically at various points on my timeline, but then go away when the user clicks. The slide is a video, and I need information to appear at precise times during the video. The ideal situation is that at (for example) :20 into the video, a layer appears automatically (thus pausing the video) and shows the user some useful information about what they're seeing in the video. Then the user can click the trigger within the layer to return to the video (I know how to use a trigger to return to the base layer, I need help with the automatic displaying of the layer if it's even possible).

If I depend on a user-clicked trigger to get to the layer, the user will not likely click at the precise time necessary and miss out on other details of the video. Or the user won't click it at all. I know I could embed slides within the video or even use callouts within the video, but this creates a passive learning environment where the user is just watching for eight minutes. Even asking the user to click out of the layer helps avoid drifting and increase the likelihood of the learner remembering what he or she just read.