Initialize unreferenced project in MVC

I have a web application solution with 2 projects. I am using ASP.NET MVC.

Project "A" has all the website elements, and it creates events to which project "B" reacts doing stuff. Project "A" is the entry point, and project "B" has a reference to "A" so that it can subscribe to A's events.

My problem is that project "A" cannot reference project "B" (that would be cyclic!), so "B" is never called (not even static constructors) and it cannot subscribe to "A" or do anything at all.

If I make "B" the entry point, sure enough, constructors and everything get called, but then I don't know how to correctly make project "A" start (unsurprisingly, the website is not created).

How do I solve this problem?