Laddergram

a cryptic puzzle by Emily Cox and Henry Rathvon

Solution
A laddergram is a form of wordplay in which one word is gradually transformed into another by a series of one-letter changes. For example, RICH can be changed into POOR in this laddergram of six steps: RICH-RICK-ROCK-ROOK-BOOK-BOOR-POOR. This month's diagram contains nine unclued five-letter words that form a laddergram. The two ends of the laddergram are the protrusions at the lower left and upper right. In the grid each laddergram word is crossed by the two words adjacent to it in the laddergram sequence. (Thus any pair of crossing laddergram words will be identical but for one letter.) The words at the extremes of the laddergram are antonyms. Answers to clues include four proper nouns.

Across

  • 1.
    Rebel blamed for a mob scene (6)
  • 5.
    Buoyant refugees finally returning to Mideast country (5)
  • 9.
    Inside closed utensils, notices fungal growths (10)
  • 10.
    Sulfur fumes receding to sinks (4)
  • 11.
    Ooze charm in speaking, to boot (6)
  • 12.
    Drifting free could be a hazard for ships (4)
  • 13.
    Scholarly merit in Latin edition (7)
  • 14.
    Large number killed (4)
  • 19.
    America takes lead from Russian bear in space (4)
  • 21.
    Book supplements and article about Ike (7)
  • 23.
    Make music with wrong guitar string (4)
  • 25.
    Steal rod coated with brass (6)
  • 26.
    Room for most of string (4)
  • 27.
    Rise, accepting welfare for youth (10)
  • 28.
    Group having no basketball equipment (5)
  • 29.
    Opposing bridges over Susquehanna (6)

Down

  • 1.
    Bee perched on a mineral rock (6)
  • 2.
    Make watch parts with folded corners (hyphenated) (7)
  • 3.
    Space weapons deadbeats discussed (6)
  • 4.
    Straighten and/or decorate (5)
  • 5.
    Solid research about Central America (6)
  • 6.
    Sure about fine bonds (5)
  • 7.
    Recited list of names, in part (4)
  • 8.
    Question we turned to one side (5)
  • 15.
    Trees died, wrapped in sheets (7)
  • 16.
    Ate leg after stewing bird (6)
  • 17.
    Swordsman in Swamp Lord auditioned (6)
  • 18.
    Cowboys' home, turning left in greenery (6)
  • 19.
    City headwear for Indians has no top (5)
  • 20.
    Old Englander's point of view (5)
  • 22.
    Italian leader catches enemy's foremost two (5)
  • 24.
    Press club (4)