CREATE TABLE table_22357 ("No. in series" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( in millions ) " TEXT)

Who wrote the episode titled 'Trojan Horst'?
SELECT "Written by" FROM table_22357 WHERE "Title" = 'Trojan Horst'
SELECT "Written by" FROM "table_22357" WHERE "Title" = 'Trojan Horst'