They have survived the initiation programmes of five of the world's toughest army units. Now, for the final, the remaining six recruits will face the ultimate test - 48 hours with the British SAS. Few are chosen and even fewer can pass the intense mental and physical challenges that must be endured and triumphed over to stand a hope of being selected for this most elite of forces. But at the end there can only be one winner. Who has what it takes to take the title of Special Forces: Ultimate Hell Week?