This is the main guitar riff :
[ Tab from: https://www.guitartabs.cc/tabs/p/pendulum/painkiller_tab.html ]
e|----------------------|-----------------------------|e
B|----------------------|-----------------------------|B
G|----------------------|-----------------------------|G
D|-----------2-2-h3-2---|-----------------------------|D
A|-----2-h3-------------|--------3-2-0----------------|A
E|-5-5------5-----------|----5-5-------0-0-1-0-1-0----|E
It's played pretty fast, so try and take it slow the first few times. You'll pick up
as you go. Sorry to all those who thinks its crap, but stuff you if your one of these people.