Studies of Kaons have had a deep impact on the construction of the Standard Model. Kaon flavour eigenstates are not mass eigenstates, leading to the phenomenon of flavour mixing in 1-loop electroweak box diagrams. These oscillations provide a method by which CP violation can be studied. The pure electroweak process is already well-understood, and so we now wish to calculate the 3-loop box diagrams contribution at O(\alpha_s^2) in QCD.