There is no "then" text in TTL's ability. Here is the text in question:
"You may place an event card attached to Ten Towers Longship on the bottom of its owner's deck to play it as if it was in your hand."
To me, it isn't a question of moribund at all. You are placing the event on the bottom of your deck to attempt to play the card as if it where in your hand. So it goes to the bottom of your deck in order to "play from your hand". This is a cost to using TTL's ability, similar to having to kneel Robert Baratheon to reuse an event. Unlike Robert, TTL puts the card at the bottom of the deck as a cost, where Robert changes where the event ends up.
So, granted I'm not certain, but I would say it temporarily would go to the bottom of the deck, you pay the gold and then put them into play "from your hand".
Edited by Slothgodfather, 27 June 2014 - 12:07 PM.