Brilliant moves

I got send this puzzle today

I thought it was very interesting and tricky. 

" Krishnan Sasikiran played a beautiful combination at the recent Prague Open ,making his victory over Ataberk Eren a serious candidate for the best game of the year .To Crack this puzzle ,you will need to find not one, but four brilliant moves in a row "

I am giving you solution right now but feel free to stop reading and solve it yourself .Puzzle does not end in checkmate but leading to it .

1.Rc8 Qd5

2.Rxg8+ Kxg8

3.d7 Qd6

4.Qe6