It?s pretty much just this repeated with a few different melody lines in the last 
bar of each repetition.
They use a lot of wah, and there?s either some reverb or similar effect as well.
Tabbed by Jarrad100

Creepy sound intro

E |--------|---------|-- Bars 3 and 4 ------------------------------------------|
B |--------|---------|----------------------------------------------------------|
G |--------|---------|-- Gradually fade in -------------------------------------|
D |--------|---------|----------------------------------------------------------|
A |--------|---------|-3h5-(repeat a-lot, listen to the song for correct amount)|
D |--------|---------|----------------------------------------------------------|

                                                        Little ad-lid melody line
E |----------|-----------|---------|---------------|
B |-------6--|--6--------|---------|-----3~-6p3~~--|
G |-------5--|--5-5p4~~--|------2--|--/5-----------|
D |-------3--|--3-3------|------0--|---------------|
A |----0-----|-----------|----0----|---------------|
D |--0-------|-----------|--0------|---------------|
                                            
                                                   
E |----------|-----------|---------|---------------|
B |-------6--|--6--------|---------|-3-1h3-0h3p0---|
G |-------5--|--5-5p4~~--|------2--|---------------|
D |-------3--|--3-3------|------0--|-------------3-|
A |----0-----|-----------|----0----|---------------|
D |--0-------|-----------|--0------|---------------|

Other instruments enter
                                                   
E |----------|-----------|---------|--(Jarrad100)--|
B |-------6--|--6--------|---------|---------------|
G |-------5--|--5-5p4~~--|------2--|--5h7p5--------|
D |-------3--|--3-3------|------0--|--------7b(1/2)|
A |----0-----|-----------|----0----|---------------|
D |--0-------|-----------|--0------|---------------|

E |----------|-----------|---------|---------------|
B |-------6--|--6--------|---------|-----3~-6p3~3~-|
G |-------5--|--5-5p4~~--|------2--|--/5-----------|
D |-------3--|--3-3------|------0--|---------------|
A |----0-----|-----------|----0----|---------------|
D |--0-------|-----------|--0------|---------------|

Then the words come in on the Verse which is just the intro repeated with bar 4 changing

If u want to know the chords for the chorus, they are: A#, G, F, A, A#, A
Then back to D for the Verse

Legend 

~ = Vibrato
b = Bend 
h = Hammer
p = Pull-off
/ = Slide up
\ = Slide down