Converting the letter sequence to their numerical equivalents, we see that the difference between them is increasing by one. This means we need a difference of seven, leading to twenty-four. Converting back to a letter, we have the answer:
X marks the spot!
!BEER
!ENGAGE
Comment 57/500
Good job, didn't get it and scrolled down and saw this. This must be the right answer
It seems to be the correct answer, nice! :)