Incorrect Quotes & Alternate Universes

wake up

What's this? A story idea? Yep! More randomness! I wanted to post because this idea has been stuck in my head for weeks!

Seán wakes up in an unfamiliar place in the middle of a war. There's nothing he remembers. Not even his name. He barely makes it off the battlefield alive and ends up in the medical barracks. Nurses take care of him and soon after, he drifts off into sleep.
The next morning he wakes up in a completely different setting. Nothing from what happened yesterday was the same. The day after that it happened again. And again. And again.
After months of new worlds every single day, Seán grows tired. He still doesn't know who he is or what he's doing. Then one day, he hears a voice. It doesn't seem to have a source, and it sounds vaguely familiar. Someone is talking to him!
Over the weeks Seán learns who he is, who the person is and what had happened to him. Now he must find a way out of this world before it's too late.

I had the idea that Seán was stuck in a coma. He had an accident and now he's stuck switching between worlds with his memory lost. Mark comes to visit him frequently, which is the voice he hears. Mark tells about things that had happened but doesn't know Seán can hear him. He has no idea he's helping his friend out of this coma he's in.

What do you think of this? What would you add or change in this? Let me know!