The Second Amendment
C Underbelly ***
Promising young Oxford writer Peter Morris had a hit a couple of years ago here with The Square Root of Minus One and confirms his talent with a scary portrait of a young American teenager about to go on a Colombine High School-style rampage. Admittedly, the piece goes exactly where you expect as Martin, alone in his bedroom, fantasises about the violent death of his hated stepmother and gradually reveals through his website a mind twisted by race hate and a festering rage at the world. But the writing and the psychology are spot-on.
The really scary thing is that you start to warm to Martin, see the brilliance of a mind crippled by emotional damage and laugh at his savage jokes. What you see in front of you, in both the restless teenage energy of the script and Ben Duhl's terrifying, compelling performance, is the slow disintegration of a personality, the tortured road to complete mental breakdown.
The horror is not at Martin's murderous impulses, but that nobody around him has noticed what is happening to him; that in the midst of such suburban affluence he should be so alone.
Till August 27. Box office: 0131-225 5105.