New RAB theory...

[carolynwhite2]

Now the full Black family tree is revealed:

http://www.hp-lexicon.org/wizards/blackfamilytree.html

what do you reckon on RAB being the Regulus Black (1906-1959) rather 
than Sirius' brother (1961-1979)?

This would make a lot more sense, as this RAB is quite likely to have 
been at school with Tom Riddle, and been one of the original DEs. 
Someone this old is much more likely to have found out or know 
something about the cave, and know enough dark magic to have a chance 
of getting through Riddle's enchantments, rather than expecting a 
frightened young boy to have done the deed.

There could have been any number of reasons why this older RAB turned 
against Riddle, and noting how many people in this tree have similar 
names, not at all unlikely that he and his step-grandson would have 
the same initals.

Sorted?

Carolyn