User:SOTO/Forum Archive/The Panopticon/@comment-4028641-20151008023030/@comment-1783865-20191105201414
From Tardis Wiki, the free Doctor Who reference
There cannot have been "a few others unknown". It has been pretty much known since the 70s that Delgado's was "at the end of the line", which does not mean that he IS the last, but pretty much states that there can only at most be one more.
And why do we not know if Pratt and Beevers are the same? That is pretty much confirmed outright by multiple instances...