Related Clues:

• This puzzle's nine longest answers use only the first half of it
• Result of splitting atom? That's only half of it
• Group of characters
• It stores all the letters one writes
• All the characters offering top dog to back
• Series whose first seven members are sung to the starts of 18-, 26-, 41- and 54-Across
• Characters moving a table outside public house
• Set of all letters
• All the letters, or not quite two?
• A through Z, collectively
• Groundwork used to catch fish — about a ton
• Keeping record, heads of Austria and Hungary make good spellers?
• 26 characters trashing a table outside pub
• Beating path, able characters
• Rudimentary material