It's no secret that corporate law can wreck your spirit.

Jobs at big firms pay more than $165,000 a year to start, but the hours are notoriously long and the work can be mind-numbing.

One former lawyer says it was utterly demoralizing too.

At the end of our source's brief stint at a major firm, she felt she had no choice but to leave BigLaw completely.

This former lawyer joined the firm after graduating from an Ivy League law school. At first, partners distributed work evenly among her "class" of associates, or young lawyers who have yet to make partner.

But then a pecking order was quickly established.

"I think law firms are very goal-oriented," our source told us. "You are going to become a partner, or you are disposable. If you are disposable, then you have a crappy life."

The "disposable" associates, like our source, often received assignments at 4:30 or 5 p.m. that partners wanted "overnight." Our source routinely worked 13-hour days.

"Probably three or five months in, it was very hard to maintain other things in my life," she says.

Her work life was made more miserable by the unfriendly atmosphere in the office. The firm once held a "diversity training" where lawyers were told they should greet one another to make people feel less alienated, but partners and senior associates balked at the notion of saying hello to underlings.

"There was major kickback from the senior associates and partners," our source says. "They were like, 'No, we don't want to say hello. My prerogative is to be an accomplished lawyer.'"

The entire experience, our source says, "was just not very humanizing."

Life at the firm got worse after after she got a bad annual review. The writing was on the wall. Our source believes her firm never intended for her to become partner.

"I think the abuses started piling up after that," our source told us.

For a while, she put one foot in front of the other and went to work.

"But at a certain point my body just turned on me," she says, "and I was just not going to physically go into the office anymore."

Her departure was not unusual. "They take in large junior classes each year, and at the end of two years most people are gone for different reasons," she says. "People just disappear."