A scenario in which Dave tells Wally to stay still whilst he does something quickly. Wally listens until someone he thinks was Dave, knocks into him. He calls out to Dave, asking what he did that for and starts in a direction the person hit him from.
Dave's not looking so he doesn't realize Wally's gone until he turns around. Panic sets in and he starts looking around, but Wally's gone gone.
It takes a good long while, but he eventually sees Wally heading towards something that'll surely kill him if he walks into it (road, over tracks, something like that).
Dave's fear is replaced with absolutely terror as he books it towards Wally, shouting at him to stop, but there's something he can't hear that's preventing Wally from hearing him. Just has Wally's about to meet his certain death, Dave's arms wrap around his waist, yanking him back.
Muffled by his face being buried in Wally's shoulder blade, Dave repeatedly calls him an idiot, not loosening his, fairly shaky, grip. Wally's makes a few failed attempts to get Dave to let go and talk to him, but eventually gives up to just let Dave calm down.
