Jada Pinkett Smith and Michael Vartan Jada Pinkett Smith and Michael Vartan

It's ironic that HawthoRNe's third season opens with a scene of bliss because almost everything that follows is heartache.

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The new season (premiering Tuesday, 10/9c, TNT) begins with a pregnant Christina Hawthorne (Jada Pinkett Smith

) preparing to marry boyfriend and baby-daddy Tom Wakefield (Michael Vartan). But the rest of the season-opener is no honeymoon: Christina is brutally attacked in the hospital parking lot, putting the lives of both her and her baby in question."I think it will be a nice surprise that it's happening so quickly," Smith tells TVGuide.com of the couple's wedding. "And I love the idea of creating something that seems so stable and then shaking it the hell up. This season is basically like shaking up everything Christina thought she knew.  [It's] stripping every belief she ever thought she had about herself and about the world and putting her through the fire."The attack on Christina naturally requires a police presence. Enter Detective Nick Renata (new series regular Marc Anthony), who still carries a flame for Christina after dating her briefly last season. His dedication to finding her attacker clearly isn't just about the police work.

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"It's not done. Not yet," Smith says of the feelings between the two. That, of course, will strain Christina's relationship with Tom, who is consumed with healing Christina and the baby — often going to irresponsible lengths to save them both. "The challenges of being a couple don't go away just because they're married," Smith says. "They actually get heightened because of incidents that happen. Just because you see them together now, you never know what happens."Christina will also be fighting other battles at the hospital when administrator John Morrisey (James Morrison) names a new director of nursing while Christina recovers. Plus, her daughter, Camille (Hannah Hodson), catches the eye of Tom's new protégé, Miles Bourdet (Derek Luke), who's going through a divorce.  "This year, Camille is really becoming a woman because Christina is really focused on so many other things," Smith says. "You can see two women that are going through a lot and just living in two separate worlds come together, try to figure some things out. ... Christina absolutely has strong feelings about [Miles], and she expresses those feelings about it, but then she kind of disappears because she's so caught up in her own stuff."

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And how will Christina come out on the other side of this drama? "I think people will be really shocked to see what the outcome is — to see where she goes from here at the end of this season," Smith says. "Christina makes enormous changes this year."