Why is my render time so long?

Im working on a project, and there is a green render line. When I hit render all it tells me the render time will take 35 hours. I already converted the files to ProRes in compressor before editing and when i dropped the clips into the sequence I had the settings match the clips. There is one camer that is different from the other two used. Could that be the problem? Ive never had a render take more than 2 hours tops!