So the other day my boss (let's call him Colfax) asked me to work on a project, but that I should not discuss it with anyone (including the other programmers on my team) and that it would have to be done outside of normal work hours. In exchange, Colfax offered me "off-the-book" vacation days equal to the hours spent on the project. When I asked Colfax if his boss (let's call him Schuyler) knew what he was offering, Colfax said that Schuyler does not know and implied that he (Colfax) would get into trouble if Schuyler found out. My boss also said that if I were to go along with this, my efforts would be remembered for "future consideration".

The work is for our employer so everything there is on the up-and-up. However, I have an uneasy feeling about the whole thing. Part of me wants to work on the project -- as it's you know -- coding and coding something cool and fairly simple. On the other hand, the whole thing seems seedy and underhanded.

Would I be a "bad employee" for refusing extra work? Or am I morally justified to not do the work?

UPDATE

I know it's been a while since I posted this question, but I thought the folks who participated in the discussion might be interested to know that Colfax quit a couple of months after this conversation. So, if I had followed along, it would have probably been for nothing. Regardless, thanks for the comments everyone.