The Unknown Companion

[James Palmer]

"Who is the third who walks always beside you?
When I count, there are only you and I together
But when I look ahead up the white road
There is always another one walking beside you
Gliding wrapt in a brown mantle, hooded
I do not know whether a man or a woman 
- but who is that on the other side of you?"

Eliot, "The Waste Land"

"360: The following lines were stimulated by the account of one of the
Antarctic expeditions (I forget which, but I think one of Shackleton's):
it was related that the party of explorers, at the extremity of their
strength, had the constant delusion that there was _one more member_ than
could actually be counted."

Eliot, "Notes on The Waste Land"

This is a remarkably cruel and subtle effect to spring on your PC's.  When
they are at the very limits of their strength, battered, broken, and out
of charges, start describing events as if there was one more member of the
group than there actually is.  For example, if there are four of them, say
"the five of you slowly make your way past the shattered remains of the
automaton."  When one of them notices and challenges you, tell him that
he's convinced there are five members of the group.  When they count, they
count four - but they're certain that there's five.  As they keep
journeying, occasionally drop descriptions of their companion - "You brush
past brown robes (or whatever) as you move to the front of the group."

There are three variations of this -

a) Mundane.  The PC's are just experiencing a genuine psychological
curiosity that affects people at extremities of fatigue.  Now, of course,
they'll go nuts trying to figure out what spell's affecting them.

b) Nasty.  A very subtle entropic is causing the effect, and may
occasionally give them false hope only to lead them into danger - a modern
will-o-the-wisp.

c) Interesting.  The figure is a manifestation of the Archetype of the
Unknown Companion, the secret helper or aid who supports the hero at his
most desperate moments.  The best way out of their situation is to follow
the (barely-perceivable) motions of that half-glimpsed figure.