一針見血

The number one; single; a; as soon as; entire; whole; all; a "one" radical in Chinese characters; also used for clarity when spelling out numbers.

A needle or pin used for sewing, embroidery, or knitting; a sharp, pointed object; a unit for injections or stitches; to sew or prick.

to see; to meet; to appear; to interview; to encounter; opinion; view; surname

Blood; the fluid circulating in the body; also used to mean tears; to stain with blood; related by blood; passionate or intense.