Workout

Warm-up (600)
2 rounds 
200 swim/100 IM

Set (900)
6 x 150 on 2:30
...50 kick/100 swim
 
Set (1800)
4 rounds
2 x 100 1:30/1:30, 1:20, 1:15, 1:10
2 x 75 on 1:05 Free/Stroke/Free
1 x 50 on :50 odd rounds: FAST even: EASY
2 x 25 on :30 odd rounds: EASY even: FAST

Cool-down (200)
4 x 50 on :55
... decrease stroke count by 1 each 25