The passenger

I didn't know you were there
until you said "hello."
You had been watching me
for I don't know how long.
I hit my head against the lamp,
as by surprise I stood up.
"Don't be afraid," you said,
"it's only me- The door wasn't locked."
The voice I'd heard in the hall
was hard to recognise.
But now we know he's onboard,
wearing our disguise.
If only you and I could trust
each other through this,
then together we could
work out who
the enemy is.