Go through utgarde keep and before you get to the last boss there is a dragon rider who lands you need to shadow step to him as a rogue before he lands, Then you can explore and if you walk in the water and around a huge area you can avoid death and find another island that is consider part of the howling fjord so It might be possible to summon.
If you walk to the other hidden island there is another copy of utgarde keep but theres an invisible wall before you get to the instance.
PICS!
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