1. 2.  3.  4.  5.  6.  7.  8.
9.               
10.      11.         
               
12.               
               
13.  14.     15.       16.
      17.         
18.    19.     20. 21.     
        22.       
23.            24.   
               
25.          26.     
               
27.               

ACROSS

1. Far-roaming disciple of doom, as embracing confused "but" thing. (8,6)

10. Pour a risky portion of toxic potion. (5)

11. Does Osama Bin-Laden (with elements of sane bias removed) pose as portentious? (4-5)

12. Lexicography and odd April letters arranged by means of dry printing process. (15)

13. Arranged one hint: a foodstuff. (6)

15. Pigs tore off on self-indulgent crusades, ... (3,5)

18. ... mostly anecdotal characters, usually seen in Queensland! (4,4)

20. Likes of (1 Across) or (9 Down) horse takes me back around. (6)

23. Dr. Ian Morrow throws do for six, and drops argument in favour of Al's prudishness. (9,6)

25. The first way: Sword and Orchid. (9)

26. Repetitively makes a profit. (5)

27. Third happiness rod turned gnome on with a most rarely used expression. (5,9)

DOWN

2. Ian, or characters in broadcasting... (2,3)

3. ...induce boring Northern characters... (5,2)

4. ...to put Ian after (half behind) a native Mexican. (6)

5. Go peg hay messily into consuming earth. (8)

6. Chatful, but confused? (4-3)

7. Award milled on a cast. (9)

8. Bright star: New York! (5)

9. Noble, quite exotic, but not too Eastern. (8)

14. One type of shake lands chap in chaos. (9)

16. SAS mines exotic instruments. (8)

17. Lampoon poor in newspaper. (8)

19. Return booty but fight for the useful chest. (4,3)

21. Support an energy gas. (7)

22. In fixed zone or not, off the mark! (2,4)

23. Animal health expert leads check of fodder crop. (5)

24. Topping a lot, a Mexican offensive. (5)