NARRATOR: It's hard to believe
today, but in medieval times,
evil was thought to be
everywhere, no more so
than here in the small
village of Troston
in the heart of East Anglia.
Locals, like the
rest of the country,
believed the devil stalked the
land, causing chaos and death.
 Neighbor turned on neighbor.
People thought the whole
world was going to hell.
NARRATOR: It was all
pretty grim, so much so
that people believed
that the church
alone couldn't save them from
this evil infecting the Earth.
Troston's village church,
St. Mary the Virgin,
is a perfect example.
It's been here since
the early 1300s.
 It's an ancient Suffolk
church, as I understand it,
the superstition written
literally on the walls.
Look at this.
You can see a hand mark there.
Is that a date?
Let's move more inside.
I don't know why I'm whispering.
NARRATOR: Inside the
church, the walls
are covered in strange
symbols that I've
never seen in a church before.
Matthew Champion has spent years
studying this curious graffiti.
 Hi, Matt.
Sorry to disturb you in your--
were you rubbing the pictures?
 I'm doing tracings
at the moment.
So what we've got is
an acetate here we
are laying over
these inscriptions,
and then we're just
marking them out.
 So how long have
these inscriptions,
bits of graffiti-- how
long have they been here?
 Well, we've got a complete
mixture on the wall here.
Some of this is dating
back to 14th century.
NARRATOR: There are
hundreds of these scratch
marks scraped into
the walls, and they
have a very creepy name.
 Are only these what
they call witch marks?
 There are a number of
these markings in here
which a lot of people
do call witch marks,
but that's really a misnomer.
These are what we
call ritual protection
marks or apotropaic marks.
And they're actually
designed to ward off evil.
So if anything, these could be
regarded as anti-witch marks.
 Anti-witch marks, yes.
 If we go and look
at the chancellery,
we'll see the whole area
is absolutely covered.
So let's go and have a
look at that, shall we?
 Yeah.
 Over at this side.
NARRATOR: But what
could they be protecting
themselves from that justified
defacing their own church?
 It might help if I actually
draw this one out for you.
 Yeah.
 OK.
I'll mark out an eye there,
take it around there.
We have a nice, bulbous
nose sticking out there.
And then we have
a big, open mouth
out there, full of sharp teeth.
And then right there, we
have a big, lolling tongue
coming right up.
NARRATOR: It's like
a scene from a Hammer
horror film, a sinister
presence in the house of God.
 So why is there an image
of a demon in church?
 In the Middle Ages,
demons were very, very real.
Demons were what
brought misfortune.
Demons were what suddenly caused
all your cattle to drop down.
Demons were what brought sudden
illness or caused sudden death.
Demons were part of this world.
The interesting
one about this is
you'll notice that
right over the top,
we have this pentangle,
this five-pointed star.
And you see it's much
deeper than the demon
that's been inscribed.
It's almost like it's been
gone over time and time again.
And it fits directly
on top of that demon,
pinning it to the wall there.
 Right.
 Essentially, it's
taking away its power,
and it's trapping it here.
So it's acting more
like a demon trap.
