There's a lot in the PT's about passing through the double door or great door as well going through a process but nothing I recall about a series of doors.

It seems exceedingly odd to me that they are about to embard on destructive testing and exploration while not even allowing a great deal of non-destructive testing.

It seems they want to be careful what they learn. This should be about as interesting as Al Capone's vault.

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Man fears the pyramid, time fears man.