Tom Riddle Question

[FrisbeeK]

No: HPFGUIDX 104882

Do we know exactly what happened to Tom's parents in the time 
between when he went to Hogwarts and disappeared and when he went 
back and killed his father?  Do we know what happened to his mother 
and whether or not the parents(with others or together) had other 
children?

Just wondering if maybe LV's mom had a thing with a royal wizard and 
perhaps the HBP is Tom Riddle's half brother.  I sort of assumed 
initially that half blood meant half muggle and half wizard; but 
what if it's all wizard but half common wizard and half royal?

This is just speculation; but a brother could have easily been 
introduced in CoS but might have given too much away so JKR waited.  
Because she introduced us to Tom's family and gave us a hint of the 
type of childhood he had (similar to Harry's); but I don't remember 
her giving us a true picture of why Tom did what he did.  What drove 
him to even want to live forever?

Frisbeek - just wildly speculating here....=)