To place this passage in context, it happens shortly after Bertin has become smitten by Durand's daughter, and has decided that he is not nearly as good a man as she deserves, and therefore changes are in order. Among other things, he has decided that it is time to get rid of the smoking habit. Bertin is a young police sniper, but in his private life he has stumbled across a murder and he is determined to see the killer or killers brought to justice.
A few days later, Bertin decided he was tired of sitting around hoping someone came up with information on the Arab boy's murder, or on undercover communists of a latter-day mutant variety, or on the ambusher Jean Blondet, or any of a half dozen other matters nibbling away at his thoughts and his sanity and his sense of duty.
He didn't have much training in investigating, but he had a notion that information could be teased out of the sorts of people who relaxed in bars during the afternoon, when more respectable persons were at work. Unfortunately for this theory, he couldn't be sure of having any of his afternoons free for the next month or so. So he took his theory a step further. If persons who lolled about of an afternoon were disreputable enough to know about horrible things, surely the folks who got started on their drinking before noon would be even more sunken and useful, especially if he caught them before they had drunk too much.
Complicating matters, he wanted a place with smoke in it. Obeying an impulse that had seemingly come from nowhere, but that had struck him as a good idea, he was trying to quit smoking. He'd borne his withdrawal woes manfully, but his resolve was wavering. To go somewhere with secondhand smoke would be a good compromise, perhaps, at least during the crisis of the first days, he reasoned. It wasn't as good as making a clean break, but the agonies of quitting were proving worse than he'd imagined, and he was willing to bow to necessity, if a fellow wanted to look at it that way. Unfortunately, anti-smoking zealots had gone before him in the part of town in which he wished to nose around. He found himself searching, and searching, for a suitable place.
He stopped in front of an establishment that had one name painted on the window, another posted over the door. He grinned at the incongruity. It brought back memories.
He'd had an uncle who bought a hotel/restaurant in a third-rate resort area. The uncle had renamed the place, but never quite got around to removing the sign bolted above the front door. He'd said it helped business, since the locals would call it by the old name anyway and would likely make their referrals to tourists accordingly. And, besides, there were any number of outdated tourism books floating about, which would recommend the old place. And so on, and so on. Bertin laughed. The old sign had stayed because, in his uncle's view of the world, to remove it was too much work. The new sign was a placard in the window because it was cheap.
The locals hadn't used the old name or the new. By unspoken agreement, the place was called what it had been dubbed two generations back by the citizenry: Malbouffe's. The word no longer meant bad food so much as merely fast food, but still, the name rankled. It was one of the hazards of buying a historic building, Bertin supposed. Sometimes it came with an insufferable nickname, if not a bad reputation.
Bertin's father, who had laughed as hard as anyone at the Malbouffe moniker, had finally taken pity on his brother and commissioned a brass plaque explaining the long history of the building, and making reference to the valued artifact above the door, lovingly kept in place by the heritage-conscious new owners (or so the sign said). Overnight, Bertin's uncle became a hero amongst history buffs who wandered through on tours. The neighbors had snickered and sneered. They could see nothing valuable in an effort to commemorate second-class efforts of second-rate dead people but, well, if it pleased the silly tourists, that only confirmed their opinion of silly tourists.
The uncle had a couple years of prosperity after that, before being wiped out by a flood. Life was like that, Bertin's father had told him.
So, all these years later, in Paris, Bertin looked at mismatched signs outside what amounted to a French pub and they tugged at his heart. He looked at the establishment that belonged to the signs, and, overall, found it strangely appealing. He thought that he might not mind too much if persons who mistook individuality-crushing legislation for progress had beaten its spirit into the earth, and therefore the management did not allow smoking. It would almost be enough that the place made him think of his now-dead uncle.
He got a whiff of tobacco smoke. That decided it. This place deserved his business. Obviously. One must support holdouts standing up against the bulldozers of conformity. The future of France depended on its spirit, after all.
He decided to get a feel for the place before he began his questions about likely murderers or bad blood between natives and immigrants. He pretended to be someone who was simply in need of a bite to eat and a coffee.
He stood at the bar instead of going to a table, putting himself close to a couple of likely looking down-on-their-luck types. He bought a cigarette off the man next to him, deciding that, after all, he wouldn't settle for secondhand smoke, not now that he had decided that to smoke in public was a worthy act of defiance.