Hello, I'm was (am) doing the Wrath Gate quest line on my horde character. Got as far as to the quest "The Battle For The Undercity" (https://www.wowhead.com/quest=13377/...-the-undercity). Can't however start the even by speaking with Thrall or turn in the quest (instantly marked as comleted). Any help would be greatly appreciated.

Cheers