The mid-Pleistocene Transition (MPT) is a crucial changes in climate dynamics, leading us into our current regime of long, asymmetric glacial cycles. However, evidence about the differences in how climate behaved before and after the MPT remains sparse and we also lack evidence to decide between theories that aim to explain the MPT. Here we hope to gather new datasets that compare climate on either side of the MPT or that offer new evidence about glacial cycles before it. Modelling and conceptual work about the causes of the MPT are also wlecome. Finally we would like to hear about work that paves the way for new projects, including plans and methodologies to obtain pre-MPT ice cores such as (but not limited to) the IPICS Oldest Ice challenge, like Beyond EPICA and other endeavours.