It is well recognized that organizations play a central role in generating inequality in employment outcomes between women and men. Women are often disadvantaged relative to men when they enter firms either because they are more likely to enter into lower paying positions or into roles that offer less advancement opportunities. What is less well-understood are the mechanisms though which women may be able to overcome these disadvantages. One theoretical solution to this problem is for women to undertake less typical career paths within the firm and move to more fecund jobs and job ladders that offer more opportunity for advancement. However, there is a risk to moving atypically, as erratic careers are often viewed negatively. We investigate this question with monthly observations of 53,311 exempt U.S. employees at a West Coast Fortune 500 tech company over an eight year period, from 2008 to 2015. We first demonstrate that jobs disproportionately staffed by women are, on average, of lower pay and lower advancement opportunities within the firm. We find, erratic career mobility, defined as a sequence of atypical job moves, results in differential outcomes for women and men. Specifically, women who move erratically are promoted faster than similarly erratic men. However, this effect is the opposite for performance appraisals. More erratic mobility by women results in lower performance appraisals than similarly erratic men. Mobility is therefore a double-edged sword for women - we refer to this as the dilemma of mobility.