Vasily Strela, teaching MIT's 18.642 Topics in Mathematics with Applications in Finance, builds the Black-Scholes framework from the idea of risk-neutral pricing. He starts with simple cases, forward contracts and options, to show how derivative prices can be pinned down without ever estimating an investor's risk preferences. From there the lecture moves into the stochastic calculus behind the Black-Scholes equation, tracing how volatility and interest rates, not expected returns, end up driving the price of an option. The second half turns practical, covering option replication and the hedging strategies that make the theoretical price enforceable in a real market. Strela works through the mathematics on the board at a pace suited to students who already have the stochastic calculus prerequisites, making this a mid-course lecture rather than an introduction to the subject.