sql - Strange behavior OFFSET ... ROWS FETCH NEXT ... ROWS ONLY after ORDER BY -

i see strange behavior of construction

select ... order ... offset ... rows fetch next ... rows  

i made simple example display (sql server version: 2012 - 11.0.5058.0 (x64) ):

create table #temp( c1 int not null, c2 varchar(max) null)  insert #temp (c1,c2) values (1,'test1') insert #temp (c1,c2) values (2,null) insert #temp (c1,c2) values (3,'test3') insert #temp (c1,c2) values (4,null) insert #temp (c1,c2) values (5,null) 

first query:

select * #temp  order c2 desc 

result ok:

3   test3 1   test1 2   null 4   null 5   null 

second query:

select * #temp  order c2 desc offset 0 rows fetch next 3 rows 

result has sorting:

3   test3 1   test1 4   null 

and last query:

select * #temp  order c2 desc offset 3 rows fetch next 3 rows 

result strange , invalid in opinion (i need 2 records not contains in previous result, instead record id=4 second time):

4   null 2   null 

can explain why sql server works strange?

use unique key column type of case:

select * #temp  order c2, c1 desc offset 0 rows fetch next 3 rows 

never faced ordering problem.