To "master the matrix", drag word fragments into the grid.
The objective is to find a place where two valid words
can be formed using the letter above and to the left.
The fragment is combined with the letter to the left and the letter above.
Add a letter to start and end of each fragment to form the words.
Look at this example ...
Moving [AT] causes two words to be revealed: MAT and OAT.
Find a home for all fragments to master the matrix.