: ...now that I think about it, after "A Murder of
: Crows", big D knows that a flood is about to hit
: the legion (The Wall, not counting LH&SC).
: "Flood" relates to The Lurker again.
: This may be stretching things, but it does fit Bungie's
: pattern of loose relation and later revelation.
: --Sting
Whoa, there, big fella! It's an interesting theory. I think there's a simpler way to explain it, though. SB has a powerful magician in his camp, somebody who used to be a big-time avatara and could do just about anything he pleased... and his name is Phelot. Being a Shade doesn't mean you lose all your powers except the dispersal dream. The D and Phelot are known to have battled each other on arrival--I imagine Phelot couldn't use his disperal dreams for fear of hitting friendlies (though I'm sure he'd be willing to sacrifice a few pesky ghols, he wouldn't want to accidentally make SB's head go pop) so he called up the hand thing--which isn't necessarily an elemental, it's just a holding device with a particularly artistic slant. This probably took a while, however, during which time the D was able to start his binding dream and get it moving Phelot's way. For some reason this is an especially slow binding dream--the D is able to influence Phelot enough to make him give you a knife and then take off like a bat out of hell, but not enough to make him go play nearby target whack-a-mole with SB; however, by the time you get to Shiver, it's become a total conversion, so to speak.
The D is definitely the more powerful magician than SB, but SB has other skillz that more than make up for the disparity. When the D gets one of the crows what he does is make sure SB can't just fly away at the first sign of trouble--which will allow Alric to corner the faceless wonder at Tharsis--but maybe also it gives the D some insight into SB's plans, i.e., flooding the wall. It's also possible that information came from some other source; Alric had plenty of scouts out, I'm sure.
BTW, what's the connection between the Lurker and floods?