M&A Advisory Firm Case Study - How to prepare and what to expect?

Got a 2 hour case study & a interview with a VP at a boutique in M&A (LMM btw) as the last round for an internship. Interviewer (We got on pretty well.) told me during the TI that I do not need to prep/learn anything for this which has left me hella confused and not knowing what to expect.

Was wondering if anyone that has been through recruiting for M&A what would they ask me broadly so I can go prep accordingly? 

Apart from learning the M&A deal process, a couple old deals the firm has done and accounting basics and valuation methods what else should I be doing? 

This is the first AC I have ever had so kinda nervous aswel. Only ever had short interviews for all the previous internships I have done.