Skyrim:Note on Summer

Skyrim: Items: Notes: Books
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ID xx0008A4
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Note on Summer

The boss says we can use one of those control rods to make the metal crawlies open the way.

Supposedly you just point the thing at one of those round waypoints and the spider does the rest, but I don't know how to fire the rod. I just hope I figure it out before I collapse from all this heat. I can almost smell my blood cooking.