Sneaking sleeping pills in with 目を盗む

As Ran sleeps, she’s carried to a sink filled with water and almost drowned. After, Conan considers the coffee Ran drank earlier must have been drugged, or else Ran would have fought back.

Since Mrs. Yone, who prepared the coffee with Ran’s help, was with Kogoro at the time of the attack, Korogo narrows the list of suspects to four who were out of sight while the coffee was being prepared.