ACROSS

 1  Seclusion of an old suite. (8)

 5  Your weapon and mine, and placed under arms. (6)

 9  Painful things-i.e., a song. (7)

10  We end with a complete defeat, to become useless. (4, 3)

11  Little Italian is needed to name a high wind. (7)

12  Nothing at dinner, for example (but something at breakfast?) (7)

13  He likes to hold hands across the table. (6, 7)

15  Racing yacht, perhaps? (13)

21  No drain for a kind of dog. (7)

22  Study Musso, if you want to get to lead. (7)

23  Ends after little interest is shown. (7)

24  Turned over, but sounds tacked-on. (7) (Hyphenated.)

25 and 26  Novel way of referring to “crews.” (4, 2, 3, 5)

DOWN

 1  Stuck, by gum!

 2  Detroit gridder and Chicago baseball player. (4, 3)

 3  The air of a Marine shows he fought on its shores. (7)

 4  Sets gold, mined from displacements. (13)

 6  True mountain agent ? (7)

 7  Pointer in the way of a compound. (7)

 8  Nominal. (8)

10  The sort which go, go upon sickness. (8,5)

14  Traitor has a stoic air. (8)

16  No longer a youngster. (7)

17  When it’s broken, it’s torn, too. (7)

18  Not very successful, unless they find, as well. (7)

19  Spoils. (7)

20  Where Maud was on a summer’s day. (6)