Towers Watson's actuarial department recruits heavily at my university in Illinois. They meet students at career fairs and host socials in order to obtain some resumes and contact information. The interview process was an initial interview on-campus. Once I passed the first around, they paid for my transportation to the Chicago office for a second-round interview. This was much more in-depth: a fancy dinner with two employees the night before (paid for by the company), and the next morning a series of 6 half-hour interviews with different employees and recruiters. It was almost entirely behavioral style questions, though one interview basically asked for stories about how I've used Excel in my work.