Theme: Four Letter Jumble - The word is FATE.
17. Noir film temptress: FEMME FATALE
28. Football-like sport played with a disc: ULTIMATE FRISBEE
43. Close kin: IMMEDIATE FAMILY
56. Ironic change in destiny ... and, literally, what happens in this puzzle's circles: TWIST OF FATE
Argyle here. We have a lot to like here. No stretching of the 'in language' themes to make them fit even though two are grid spanners. Many six letter fill and a good mix overall.
These two partnered before on a BuzzFeed crossword last year. Food-themed Star Wars puns. LINK
1. Solidifies: GELS
5. Extends, as a building: ADDS TO
11. Triple __: liqueur: SEC. An orange flavored clear liqueur.
14. Golfer Aoki: ISAO. Isao Aoki, crossword regular.
15. Unfortunate event: MISHAP
16. Thurman of "Kill Bill": UMA. Also a regular.
19. Writing implement: PEN
20. Therapeutic ointment: BALM. I swear by it.
21. Tenants: RENTERs
23. Engineer Nikola: TESLA. A former regular.
25. "__F!": pre-weekend cry: TGI. A bit early for Thank God It's Friday.
27. Homer Simpson's wife: MARGE. She of the blue hair.
31. Falsehood: LIE
32. __ Angeles: LOS
33. '50s prez: IKE. DDE, Dwight D. Eisenhower, the 34th President.
34. Kareem's former name: LEW. Kareem Abdul-Jabbar was Lew Alcindor. (Basketball)
35. Dangerous current: RIPTIDE. I know you should swim perpendicular to one if caught in it. Don't try to swim straight back to shore. Today's PSA.
37. Female pronoun: SHE
40. Cupid's mo.: FEB. Valentine's Day, Tuesday, February 14, 2017.
41. Year, in Spain: ANO. 6-Down. Day, in Spain: DIA
42. Ate: HAD
49. "__ Rae": NORMA. Norma Rae is a 1979 American drama film.
50. "__ who?!": SEZ "Sez IMDb, that's who!"
51. Execs, or outfits hanging in their closets: SUITS
52. Goes on the offensive: ATTACKS
54. Gentle: SOFT
55. Life story, briefly: BIO. (biography)
61. Egg cells: OVA
62. Transition slowly: EASE IN
63. __ out a living: EKEs
64. Crossed (out): Xed
65. Same-as-above marks: DITTOs. "
66. Fender damage: DENT
1. Animated Internet file suffix: GIF. (Graphics Interchange Format)
2. Suffix with Siam: ESE
3. Meaty dish that would make Mary sad?: LAMB STEW
4. Mogadishu native: SOMALI
5. Radio band-switching switch: AM/FM
7. Hrs. that begin when we "spring forward": DST. Daylight Saving Time 2016 began at 2:00 AM on Sunday, March 13 and ends at 2:00 AM on Sunday, November 6. Another Public Service Announcement.
8. "Doctor Zhivago" actor Omar: SHARIF
9. "Tall" story: TALE
10. Amateur night at a comedy club, e.g.: OPEN MIKE
11. Exquisite: SUPERB
12. Come into view: EMERGE
13. As far as the eye __: CAN SEE
18. Jack of old Westerns: ELAM. Just one of his many deaths.
22. Stun with a gun: TASE. Jack was being shot long before tasers.
23. Rock's Jethro __: TULL
24. Nobelist Wiesel: ELIE
25. Sporty sunroof: T-TOP
26. Develop in the womb: GESTATE
29. "I was with my girlfriend all night," say: ALIBI
30. No longer encumbered by: RID OF
35. Edited: REDACTED
36. "Mockingbird" singer Foxx: INEZ. A different video for Splynter here.
37. Asian mushroom with an odd spelling: SHIITAKE
38. "Freeze!": "HALT!"
39. Breyers competitor: EDY'S Ice cream.
40. Storm relief org.: FEMA. (Federal Emergency Management Agency)
43. Packed up for shipping: IN A BOX
44. Whodunit reason: MOTIVE
45. "The Wind in the Willows" croaker: MR. TOAD
46. Help out: ASSIST
47. Dating from: AS OF
48. Bungled: MUFFED
53. "The Bridge on the River __": KWAI. 1957 British-American epic war film.
54. Daughters' brothers: SONS
57. Part of a tennis match: SET
58. Padre's hermano: TIO. father's brother/uncle
59. On a scale of one to __: TEN
60. Approx. figure: ESTimate.