καὶ ἐὰν μὴ προκαταλάβῃ αὐτοὺς διὰ τάχους, μείζονα τούτων ποιήσουσιν, καὶ οὐ δυνήσει τοῦ κατασχεῖν αὐτῶν.

1. καὶ
   and
2. ἐὰν
   if
3. μὴ
   not
4. προκαταλάβῃ
   preempt
5. αὐτοὺς
   them
6. διὰ
   through
   because of
7. τάχους
   speed
8.  
   ,
    
9. μείζονα
   greater
10. τούτων
    of these
    these
11. ποιήσουσιν
    they will do
12.  
    ,
     
13. καὶ
    and
14. οὐ
    not
15. δυνήσει
    you will be able
16. τοῦ
    of the
    the
17. κατασχεῖν
    to restrain
    to seize, to hold
18. αὐτῶν
    their
    of them
19.  
    .
     

And if you do not seize them beforehand through speed, they will do greater things than these, and you will not be able to restrain them.