While electric-magnetic duality is a symmetry of many supergravity theories, this is not the case for the N=8 gauged theory. Surprisingly, it was recently shown that this rotation leads to a one-parameter family of SO(8) supergravities. It is an open question to what extent these theories describe different physics; in other words, what the period of this parameter is. We will start with a pedagogical introduction to this one-parameter generalisation. Depending on time, we will then touch on several aspects regarding its periodicity, including triality and stability.