Across:
   1.  Often we hear it suggesting the last score of centuries (5)
   4.  Sister on point takes one of four operational units (9)
   9.  Sanctimonious have "no worries" with us (9)
  10.  Soldier ... although the odd ones spy (5)
  11.  8 dn. for us: sly trip route I worked out (15)
  12.  It will help you save face - you'll see (5)
  14.  I, Ben, had it otherwise occupied (9)
  17.  Toss tern chips closer to opening of tube (9)
  18.  Brush with a wounded beast? (5)
  19.  Parts of script perhaps which were updated by 3 dn. Henry (10 5)
  22.  He might grab bible, or perhaps only part (5)
  23.  Halt rot in mixed race (9)
  24.  Faithful bonds? (9)
  25.  First deployment sunk, scattered forces under water (5)
Down:
   1.  "Sands" perhaps a verb as is formulated (9)
   2.  A month without saint ... just right for seer (5)
   3.  Able to make something out of ideas, as per entire neural network (15)
   4.  A few worthy of further consideration - so the rest lie about lacking any energy (9)
   5.  Surprise result of 6  (5)
   6.  Ruffled dumb bodice - a lost design (15)
   7.  Poles said to be attractive (9)
   8.  With low cunning, Stallone drops an 'S' when repeating his tag (5)
  13.  Young student strangely choosy about playing lob (9)
  15.  Chins roam about in higher parts of music (9)
  16.  Doctor points and verbally performs treatments for wounds (9)
  19.  Danger of ripe turning rotten before end of fall (5)
  20.  Trust? Ask is just odd for this African (5)
  21.  Could they make the carbon chains in this any longer? (5)