Over four months the BBC's Paul Wood and cameraman Fred Scott were smuggled in and out of Syria to report on the country's struggle for democracy.
In February they met a group of rebel fighters near Homs - the toughest centre of resistance to the country's police state.
The rebels were preparing to attack an army base, but many of them had only recently defected from the Syrian Army.
And the men they were attacking in the base had until recently been their comrades in arms.
Panorama, Homs: Journey into Hell, BBC One, Monday, 12 March at 20:30 GMT and then available in the UK on the