Load page before faq_start

[stryka]

I am about to create a plugin.

How would i create a plugin that loads a seperate page before another one starts... for example... lets say i wanted you to check something first before i load the FAQ page... i assume that the plugin would execute at faq_start.... but how do i call the new page/template? Or another example would be loading a AD page before i load the main page... not what i want to use it for but i was just throwing in another example...

So once the user sets a session value on this pre page... i want it to proceed to intended desitination... after he/she clicks...