Viking: Battle for Asgard Q&A

how do i get the gems to fuse with the amulet so i cn summon the dragons

where do i find the second amulet to summon the dragon

how do i get the amulet that lets me summon the dragon

i am at caldberg but i cant get in to charge my dragon gem mugin plz help
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theres this place with a bridge called holdenfort barracks.i dont know how to go to tehre and free them!!!.can someone help me?