A file's own details (lstat) may be read from the disk as a directory is, so a directory of tens of thousands of files was read without a look and the header's promise that no burst is longer than PaceLook did not hold. The walk now asks the pacer before each file as well; the 250 ms gate makes that a clock read per file. A test with one directory of twenty files fails without it. The clock is read once after a run of pauses, and the constants test says that it guards the constants only.