Hmmm. Thinking about it . . .
Reynir can travel from one dreamspace to another. And Reyner can still get to Lalli's dreamspace.
Lalli's problem seems to be that he's not in his own dreamspace, but in Emil's.
If Reynir can find out that that's what happened, can he get to Emil's dreamspace, get Lalli, and guide him back to where he belongs?