The index command to thl provides a list of all the available THL files and the sequence number range stored within each file:

shell> thl index
LogIndexEntry thl.data.0000000001(0:113)
LogIndexEntry thl.data.0000000002(114:278)
LogIndexEntry thl.data.0000000003(279:375)
LogIndexEntry thl.data.0000000004(376:472)
LogIndexEntry thl.data.0000000005(473:569)
LogIndexEntry thl.data.0000000006(570:941)
LogIndexEntry thl.data.0000000007(942:1494)
LogIndexEntry thl.data.0000000008(1495:1658)
LogIndexEntry thl.data.0000000009(1659:1755)
LogIndexEntry thl.data.0000000010(1756:1852)
LogIndexEntry thl.data.0000000011(1853:1949)
LogIndexEntry thl.data.0000000012(1950:2046)
LogIndexEntry thl.data.0000000013(2047:2563)

The optional argument -no-checksum ignores the checksum information on events in the event that the checksum is corrupt.