Basics:

Griddlers are solved using number clues to locate solids (filled-in squares) and dots (empty squares) to reveal a picture.

Each column and row has a series of numbers next to it. These refer to the number of adjacent squares that should be filled as solids. If more than one number appears, that line will contain more than one block of solids.

The solid blocks must appear in the order that the numbers are printed. For example, a row that contains the numbers 11.5 would contain, somewhere, a block of 11 adjacent filled-in squares (solids), then a gap of one or more empty squares (with dots in) and then a block of five adjacent filled-in squares.

No. 1551: Extra Guest