Well, look who's breaking bad now!  Debra Morgan dropped quite a bomb on her brother in the ultimate moments of Sunday's 'Dexter' episode "Chemistry," one that will likely change their entire relationship across the rest of the series.  Meanwhile, Hannah McKay (Yvonne Strahovski) won't know what hit her, now that Deb's out for blood!  So has the Miami Metro lieutenant completely joined the dark side, or will she relent in her quest for justice?  Watch Deb go off the rails in the latest clips from next Sundays's all-new 'Dexter' episode "Argentina!"

'Dexter's Hannah McKay had better watch her back now that Deb wants justice that the legal system can't provide, and has broken bad enough to ask her brother to be the one to plunge the knife!  Little does Deb know that Dexter already attempted the murder once, only to end up plunging...well, something else.

Surely Dexter won't murder his new-found love interest on the orders of his now-complacent sister, but how will he quell Deb's murderous rage in next Sunday's "Argentina?"  As the new clips from the episode reveal, he'll certainly have to tread lightly to avoid losing both his sister, and new-found squeeze.  And how long will it be before Deb eliminates the middle man, and goes after Hannah herself?

Check out the latest clips from Sunday's all-new 'Dexter' episode "Argentina," and give us your predictions on what Dexter and Deb will do in the comments!