Taxi-drivers in Belfast live on their wits. Every time they are given a job, every time they pick up a fare, they calculate the risks.
"You're always judging a situation," says Chris. "The moment someone gets into the car you're thinking, `Who are they? Do I recognise them? Where are they from?' When it's a stranger, you wonder, `Do they look like a killer? Could they have a gun? Could this be my last fare?' "
Chris is not paranoid. Taxi-drivers, particularly Catholic ones, have long been in the front line.
"We're the softest of soft targets," he says. "We're available without any protection 24 hours a day in all areas."
Over the years several Protestant taxi-drivers have been killed by republicans. However, the vast majority of murdered drivers have been Catholics.
They have been killed by gunmen posing as passengers; shot as they arrived for hoax jobs; riddled with bullets as they sat outside their depot or a pub, waiting for a fare.
Seven were shot dead in 1991 alone. The pattern seems to be starting again. Two have been killed within the past fortnight.
Larry Brennan (52) was sitting in his car outside Enterprise Taxis, on the Ormeau Road in south Belfast, when he was shot through the window. A gunman opened fire on John McFarland as he responded to a hoax call in Downview Park in north Belfast 10 days ago. He was hit in the head but managed to drive off.
A week later, a gunman entered Metro Cabs nearby, but his weapon jammed and he ran off.
Last Saturday night John McColgan (33), who worked for STS in west Belfast, picked up two men from a pub in Andersons
town. His body was found dumped in the middle of the road 15 minutes later.
He had been shot five times in the back of the head at pointblank range. His killers, who had posed as passengers, escaped in his car. Mr McColgan was married with three children.
Chris, who also works for a firm in west Belfast, knew him well.
"It could have been any of us. There were no precautions John could have taken. If he had been going into a Protestant area, he probably would have been on his guard. But who would be suspicious of guys out for a drink in a Catholic bar in the heart of west Belfast?"
It is a sign of the times that none of the taxi-drivers interviewed was prepared to give a surname.
Steven, who also works in west Belfast, says: "Shooting us is a gift for loyalists. It's much easier than going for someone in a shop or a pub.
"Once the killers are in the car, the driver is trapped. He has nowhere to run and no chance of survival. Even the worst shot in the world couldn't miss hitting someone so near them.
"It's a very efficient operation. The driver is the target, his car is the getaway vehicle, and the only eyewitness ends up on a slab in the mortuary."
There are rules of survival in the taxi business, according to Paddy, who works in a depot in south Belfast. "Various things should set off alarm bells in your head.
"If a fare is going somewhere and then changes direction. If someone asks you to stop so they can be sick and you're suspicious of them. If you get a call to a loyalist area which isn't a regular and the house is near an entry or waste ground. You have to be very, very careful in all those situations.
"You should never judge anyone on initial appearances. Loyalist killers have worn Celtic and Republic of Ireland football jerseys. They have had women with them and women have lured drivers to a spot where someone else is waiting with a gun.
"You always have to be on your toes. It only takes one mistake, one bad call, and it's goodnight. It's hard to get it right all the time. You mightn't be thinking, you might be tired, you might be flattered by a pretty face."
It is illegal for taxi-drivers to carry offensive weapons, although some break the law and keep hammers under their seats. But, as Paddy points out, "a hammer isn't much use against a gun."
Another driver, Donal, says he drives a taxi only very reluctantly. He has three small children and his wife is pregnant.
"It's an awful job. It's so hard on your family. On Saturday night, my mother heard that a taxi-driver was shot and his body dumped up the road.
"She didn't want to alarm my wife so she just went to the scene of the shooting herself to see if it was me. The RUC asked her to describe my car and when she did they said, `It's OK, you can go home. It's not your son.' "
Jim, who works in north Belfast, says: "You never stop thinking that by the end of the night your brains could be splattered over the dashboard. My wife is worried sick.
"My wee girl screams the place down when I'm leaving. The night after John McColgan was shot the tears were streaming down her face. She grabbed hold of me and wouldn't let go. But I have to taxi. How else can I put coal on the fire and bread on the table?"
Marty, who works in Andersonstown, says Catholic taxidrivers have traditionally been tortured by all sides. "The Provos hijack our cars, the RUC fine us for the slightest wee thing, and the loyalists murder us. You can't win."
But Marty has a plan of action in the event that he picks up a suspicious fare. "If a face doesn't fit or somebody says something strange, I'll immediately drive into a garage where there are people and security cameras.
"If that's impossible, then I'll start increasing my speed. They won't shoot if the vehicle is moving fast. They would be risking their own lives.
"I'll tell them I think they're loyalists and I'll threaten to ram the car unless they produce ID showing otherwise. If they don't, I'll crash the car into a lamp-post, a tree, or a cop Land-Rover. Too many other drivers have just panicked or started praying.
"If I'm going to die, I'll take the bastards with me."