Beer Brand that starts with the letter D.?!

Okay while is was in London we ate a very nice restaurant called the paramount. While we were there we had a beer that started with the letter D. I know the alcohol level was very high in it. It tasted like someone mixed vodka with blue moon. Anyway, it was really good. can someone help me remember the name. I've tried google no luck. But I am very sure It started with the letter D.