Ducky says, ".. like a cat and mouse game. Reminds me of........ a part of my life that I will share with you later." A cat and mouse affair was a story in Volume 2, no 1 of The Man from U.N.C.L.E. (1964) Magazine. This is one of a number of references to the fact that David McCallum played Ilya Kuryakin in an earlier part of his life.
Vance pays Gibbs some money and makes reference to it being for a danish. In Enemies Domestic (2010), Vance gets mad and smashes Gibbs' danish. Gibbs gets upset, and Vance says he will pay him back.