I go beyond the bard to bring you a Shakespeare-era tragedy, “The Spanish Tragedy” by Thomas Kyd. This play heavily influenced “Titus Andronicus” and “Hamlet”, and is one heavy hitting revenge drama of epic proportions.
Major Character List, in case you want a cheat-sheet:
Hieronimo: Father to Horatio, Lord Marshal of Spain and protagonist
Lorenzo: Brother to Bel-imperia, nephew to the king of Spain and villain
Bel-imperia: Sister to Lorenzo, former lover of the deceased Andrea and now lover of Horatio, niece to the king of Spain, and our heroine
Horatio: Hieronimo’s son, murdered by Lorenzo, lover to Bel-imperia and friend to Andrea
Balthazar: Prince of Portugal, living in Spain since his capture in the war. Loves Bel-imperia, it is unrequited. Also a villain
Andrea: Died in the war, back to watch the mayhem. Friend of Horatio and former lover of Bel-imperia.
Pictures shown are of the Hyperion Shakespeare Company production of “The Spanish Tragedy” from 2010, which I had the pleasure of directing.
**Pictures by Annie McGrath, producer on the show.
For the rest of the show info: http://www.hyperionshakespeare.org/the-spanish-tragedy.html
Text of the play: http://www.elizabethanauthors.org/span1.htm
Youtube with Derek Jacobi: http://www.youtube.com/watch?v=DDuvqnsKXl8
theshakespeareminute 
Really stimulating! I am so enjoying these videos!!
One question: when you said “conversion”, did you mean “redemption” or “salvation” or were you using that word in a certain context, for example, as a term of art?
Chevy
I believe “The Spanish Tragedy” is a very neglected play. As for it being a precourser to “Hamlet,” I am surprised that you did not make mention of Thomas Nashe’s comments in his preface to Robert Greene’s “Menaphon” (1589). Talking about Kyd, Nashe says. “He will write you whole Hamlets, I should say handfuls of Tragical speeches.” This implies that Kyd actually wrote a play (now lost) entitled “Hamlet,” that whoever wrote Shakespeare later adapted.