4  Ancient people from the east circling singular unknown river (8)

10 One local current shape unchanging in character (7)

11 Loafed around; made a forward thrust, holding nothing (7)

12 Joy of good shelter (4)

13 Infectious disease maybe produces sign in time (10)

15 One settling overseas before accepting fighter (6)

16 Terror about European cargo (7)

20 Casual dismissal of sailor's cry (5-2)

21 Slovenly son, idle about everything at first (6)

24 Cunningly, I slyly bill this nincompoop (5,5)

26 Knowledgeable about preposition (4)

28 Rearranged letters of a horse and sheep (7)

29 Blossoms following reduced success initially (7)

30 Seal and send boxes a long way to the west (5,3)

31 Depression concerning obsolete tax (6)

 1  Old boys were these once (5,3)

 2  Prepare sentence for when audience is greatest (5,4)

 3  I carefully study symbol (4)

 5  Joins, welcoming one who might serve? (8)

 6  Lassies, partners for 1 down (5,5)

 7  Knowing otherwise conceals oblong block of gold (5)

 8  Daughter is entering almost without feeling, going without clothes (6)

 9  Unusual bream of brownish-yellow colour (5)

14 Serious measures in funereal places (10)

17 Man and a daughter combine for an illustrated chapter heading (9)

18 Appeal involving international fellow, one who presides (8)

19 Sleep-like state of curiously phony sis (8)

22 Attack a small project (6)

23 Float swirling on high (5)

25 To study, lecturer has to make money (5)

27 Wagoner abandoning conflict separately departed (4)