This question also has an answer here (in German):
http://german.stackexchange.com/questions/31705
My german is bit better now but recently one of my colleagues corrected me saying "Du sagst nicht immer in der richtung, manchmal passt in die richtung auch".
I remember that in is always dative.
The challenge was that he could not explain me the cases in English. Could someone here explain me with an example?