Have you ever had to find out what happened to your SQL Server. Who deleted that data? What event triggered something to happen. Sometimes all you have is a transaction log backup as your source of information. Reading a transaction log file backup is not that easy, but it isn't that hard either. You just need to use the undocumented fn_dump_dblog. I usually do this in a temporary database, to not interfere with anything else.

Here is a quick example:

USE ScratchDB

GO

SELECT * INTO DUMPLOG FROM fn_dump_dblog (NULL, NULL, N'DISK', 1, N'V:\DBBackup\Tran Log\MY_LOG_20180702_124501.trn', DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT, DEFAULT);

and then start reading through the results

SELECT [Current LSN], [Transaction ID], [Transaction Name], [Operation], [Begin Time], [PartitionID], [TRANSACTION SID]

from DUMPLOG where [Begin Time] > '2018/07/02 12:40:00:000' order by [Begin Time];

Hopefully from this you can track down that issue - or at least have a bit more information to help solve the puzzle.