The way up is death

When a mysterious tower appears in the skies over England, thirteen strangers are pulled from their lives to stand before it as a countdown begins. Above the doorway is one word: ASCEND. And so begins a race to the top, through sinking ships, haunted houses and other waking nightmares, as the group fights to hold onto its humanity, while the twisted horror of why they're here grows ever more apparent - and death stalks their every move.