The puzzle’s number 2468 was printed above the grid, hence ‘The theme is confirmed by the information provided.’ Letters deficient in the wordplay of eighteen clues spell out TWO, FOUR, SIX and EIGHT in rows and columns 2, 4, 6 and 8 respectively. The title, a pun on ‘No Entry’, alluded to animals entering Noah’s Ark 2 by 2, reflecting the increments of 2 in the puzzle number.