We pushed through the growing crowd. The bike's speedometer was stuck somewhere over 50. Following Whalen, we entered the ring of spectators and saw the cyclist sprawled on the road, still in his helmet, surrounded by broken glass and paramedics. O'Hara was already questioning witnesses.

Just as the victim was being put into the ambulance, a young man claiming to be the owner of the bike appeared, fuming. Looking at his cycle, he began snarling obscenities at the victim, who had apparently borrowed it.

"Is he dead? I hope he's fucking dead," he growled, kicking the useless machine. "Who's gonna two this?"

Then there arrived the victim's mother. Still in curlers and carrying a forgotten hot fudge sundae, she approached the two officers, wailing. "Please tell me it ain't him, please tell me it ain't him," again and again at the top of her lungs. Gently putting her sundae on the trunk of the cruiser, O'Hara led her away, quietly trying to console her.

The 20-year-old victim was rushed to a nearby hospital, where he was reported in stable condition early yesterday.

For O'Hara and Whalen, the incident apparently dredged up memories of the assignment both cops agree was one of the toughest.

"We had to tell a woman that her daughter had died," Whalen recalled. "Michael couldn't find the words. That was a tough one. You want to get emotional, but you're not getting paid to be emotional. You can't take your work home with you."

But sometimes, work can hit close to home. O'Hara was particularly disturbed by the case he handled three weeks ago of a 72-year-old man who had allegedly sexually molested a 7-year-old girl. O'Hara has a five-year old daughter.

I was trying to talk to this girl and saving to myself, would I talk to my daughter like, this?" O'Hara said. "The guy said. I We want to has sex with you. I'll give you money. This was a 7-year-old kid. Then you arrest the gay and you gotta treat like a gentleman. Sometimes it appalls you but life goes on."

Atimes, life for the two officers has been appalling. Like the old woman, felled by a heart attack, who had been partially eaten by her cats before her neighbors noticed the smell. Like the man who had tied a shotgun to his head, stuck the barrel in his mouth, and pulled the trigger.

They had done a lot, too. Whalen said that while trying to get a badly stabbed man into an ambulance, he had accidentally stuck his hand into the victim's intestines. Walking through the dark with nothing but flashlights and instinct, the two cops had stalked a suspect who was toting a submachine gun.

Perhaps the best defense these man have is their sense of humor. O'Hara, for instance, followed the story of two children accidentally shot outside a bar with a riotous description of a 300-pound halter-topped nymphomaniac who frequents the spot. All of the officers seemed ready for a joke.

There is no small amount of absurdity in a policeman's life. At 10:39 p.m., we got a call in the Savin Hill area of Dorchester. A woman had reported hearing a burglar inside her building, and as we pulled up in front of the dilapidated three-story apartment house, flashing the spotlight against its facade, our stomachs knotted in tension.

As we approached, the curtains parted in the first-story window, and an old woman who looked like Ichabod Crane warbled, "He's in here! He's in here!"

Our pulses quickened when Whalen, hand on his gun, rushed into the blackness of the main hallway. Nothing happened.