어서 막다

block or stop it

막다 means to block, stop or prevent, and the clause in front normally gives the means or the step before it: going over and blocking it, taking that as the last line and blocking there, having the power to block it at all. These lines are thinner than the count suggests, since several of them contain fixed adverbs that only look like the pattern, such as the words for continuously and accordingly. The core is safe: 막다 is the stopping verb, and what precedes it is how the stopping is done.