The Salvatore Sister

Arabella Salvatore is the long, lost Salvatore sister to Damon and Stefan. Having been locked up for the better part of a century by the infamous Katherine Pierce, Arabella hasn't seen the outside world since 1864.

When she returns to her brother's lives, she isn't prepared to be dragged into their fight against all evil to protect Elena Gilbert, the doppelgänger.

Then, Arabella meets Klaus Mikaelson.

Neither of them can deny the chemistry that the pair have nor can they avoid their attraction. No matter how hard either of them tries.

Set in seasons 2-4 of TVD.