plumb the depths (of (something))

to carefully examine something in order to understand or explain it.

Who would want to plumb the depths of the criminal mind?

Etymology: based on plumb line (= a cord with a heavy piece of metal attached to it, used to measure the depth of water under a ship)

• make all the difference in the world
• make all the right noises
• make all the running
• make a long story short
• make a man of
• make a man of someone
• make a man out of
• make a man out of someone
• make a mark
• make a martyr of
• make a martyr of someone
• make a martyr of yourself
• make a meal of
• make a meal of something
• make a meal out of
• make a meal out of something
• make amends
• make a mental note
• make a mess of
• make a mess of something
• make a mockery of
• make a mockery of something
• make a monkey of
• make a monkey of someone
• make a monkey out of