Summary:

Two sisters have no idea what they are getting into when they board a fancy ship going from Spain to Brazil. The journey is filled with love, death and shocking secrets that arise. The show is fast paced showing not only the sisters journey, but the twisted stories of those close to them. It will keep you wondering who the bad guy really is until the very end.
The sisters go through many challenges and struggles as they untangle a dark web of family lies. The other passengers close to them also deal with their fair share of trouble, showing their true colors.

Personal opinion:

I thought this was a really interesting show with many intriguing twists and turns. I admired Eva a bit more than her sister due to her more determined and curious approach to things. I did also lose quite a bit of respect for Caroline in season 2. After knowing some of the things her husband did, she blindly chose to stick by him.
The story stays interesting with the added subplots of secondary characters in both seasons who are involved in troubles and murders of their own. In season 2, a group of new members are introduced and even a ghost.
The fact that they are all stuck on the boat together only adds to the suspense and drama. When they finally reach port in season two there is an action packed ending. Certain situations are left unresolved, leaving some drama for season 3.