Dragon Age 2, Act 2, Repentance & the Sebastion Character

Can you try repairing the game? Right-click the game panel in Origin and you should get this option. 

If this has no effect, try changing the graphics settings to low and give it another shot. 

Thanks. 

I reinstalled the program, tried repairing, and then when the situation reoccurred, I hit ESCAPE a few times (don't remember why, unless out of sheer frustration),  but on the fifth ESCAPE, the game continued without a hitch.  Huh!

@johncleeds

It's a rare DLC conflict. It can happen if you have The Exiled Prince, Legacy, and patch 1.04 installed. Note that there is another area later in the game where hitting escape won't work, so you'll need a permanent fix.

There's a lengthy discussion and solution in the following thread: http://answers.ea.com/t5/Dragon-Age-2/Freezing-issue-in-The-Exiled-Prince/td-p/219604

The solution further in worked for me: http://answers.ea.com/t5/Dragon-Age-2/Freezing-issue-in-The-Exiled-Prince/m-p/1413440#M1862