What

You attempt to restore a transaction log and you receive an error similar to the following:

Server: Msg 4305, Level 16, State 1, Line 1 The log in this backup set begins at LSN 188000000107200001, which is too late to apply to the database. An earlier log backup that includes LSN 188000000105900001 can be restored. Server: Msg 3013, Level 16, State 1, Line 1 RESTORE LOG is terminating abnormally.

How

There are one or more transaction log backups that need to be restored before the current transaction log backup.  In the example above, you will need to first restore a transaction log backup that contains LSN 188000000105900001.

If you have access to the server where the backup was made, and assuming that the backup and restore history tables still contain the data, you can run the following query to list out the transaction log backups that need to be restored in sequence (replace the database name with your database name):

SELECT b.physical_device_name, a.backup_start_date FROM msdb..backupset a INNER JOIN msdb..backupmediafamily b ON a.media_set_id = b.media_set_id WHERE a.database_name = 'pubs'  AND a.type = 'L'  AND a.first_lsn <= 188000000105900001  AND a.last_lsn >= 188000000105900001 UNION ALL SELECT b.physical_device_name, a.backup_start_date FROM msdb..backupset a INNER JOIN msdb..backupmediafamily b ON a.media_set_id = b.media_set_id WHERE a.database_name = 'pubs'  AND a.type = 'L'  AND a.first_lsn > 188000000105900001 ORDER BY 2

If you do not have access to the backup history tables, or if the data has been purged, you'll need to inspect the header of each backup file in find out the LSNs that are contained therein e.g.

RESTORE HEADERONLY FROM DISK = 'g:\backups\pubs_log_20080521 1020.bak'

You will need to start restoring from the backup set where LSN 188000000105900001is backed up in.  You use the FirstLsn and LastLsn values for reference.