On a quiet weekend before Christmas, Capitol police responded to an alarm that told them someone might have broken into a first-aid station in the Capitol. The "intruder" they found was Heather S. Foley, the wife of House Speaker Thomas S. Foley (D-Wash.). And she had just finished giving herself an injection of something.

Heather Foley was just as surprised as the police. The injection was her regular shot for allergies. Heather Foley didn't want to bother the resident Capitol physician on a holiday weekend, so she did what comes naturally to someone who is used to getting her way on Capitol Hill. She called on the office of the architect of the Capitol -- the full-time staff that oversees building work -- and asked for someone to take her to the first-aid station with a key.

Neither Heather Foley nor the staffer with the key knew that the room was wired to an alarm as part of a system that protects the offices of the Capitol physician.

Heather Foley, who is also the chief of staff for her husband's office, has her private doctor's permission to store her medicine in the first-aid station, where a nurse usually administers the shots. The Capitol physician, Robert Krasner, was reportedly upset to hear that Foley had bypassed the nurse and the lock.

Capitol Hill police did not arrest her and didn't file a report. The only evidence of anything abnormal that day was a note that the alarm went off.

In retrospect, Heather Foley now wishes she had handled it differently. It would have saved her some embarrassment. But it would have been entirely out of character. Heather Foley undoubtedly wields more power on Capitol Hill than any speaker's wife in congressional history. If she needs to get into a room, she makes a call and someone appears with a key.

Foley is the soul of tact and diplomacy, but his wife is the hammer. She is a tough, savvy tactician and a demanding boss. It is often Heather, rather than Thomas Foley, whom members of Congress call on for favors or advice.

Heather Foley has little interest in political schmoozing and protocol. Her dress often can be called "casual" by fussy Washington standards. She rarely attends the gabby functions that attract congressional spouses. Other spouses choose do-gooder causes. Heather Foley gets down and dirty with the politicians.

And she speaks her mind, as former speaker Tip O'Neill found out. Heather Foley doesn't like tobacco smoke, and she once stunned a high-powered leadership meeting on Capitol Hill by asking O'Neill to snuff out his trademark cigar.

Her blunt manner does not hamper her clout. She is considered by many to be the most powerful staffer in the House. Not only is she the speaker's gatekeeper, filter and adviser, but she also helps divvy up Capitol office space.

Heather Foley works long hours. The day she decided to help herself to the first-aid room, the Capitol was a ghost town. It was the Saturday before Christmas and she was one of the few not on vacation.

Her salary makes her a bargain for the taxpayers. Her husband wrote the anti-nepotism bill, and she works for free.