Not for the first time in my life, as I left the new show at the National Portrait Gallery, I was moved to mutter: “Thank heavens for the Queen.” Once again, Her Majesty had saved the day. Were it not for her loan of a wall full of commanding Holbein drawings from the Royal Collection to the exhibition entitled The Encounter: Drawings from Leonardo to Rembrandt, that exhibition would be a poor event. Short on quality. Short on direction.

It is the fate of the National Portrait Gallery to be searching continuously for angles. Portraiture is, after all, a straightforward affair. Over here you have the artist. Over there you have the sitter. One records the other. And that’s it. Finding inventive ways to present this exchange is, therefore, a museum challenge that encourages much smoking of mirrors.

The problem with the angle attempted by The Encounter is that it isn’t an angle. Every portrait ever produced is the result of an encounter — it’s all a portrait can be. Putting a definite article in front is not enough to give this effort any true purpose or meaning. As for the subtitle, Drawings from Leonardo to Rembrandt, it’s a tease. Neither Leonardo nor Rembrandt is represented here in a significant fashion. If you ignore these directional problems, you are left with a drawing show in which various Old Masters of various levels of talent have been arranged in a string of sections that are supposed to frame telling aspects of Old Master portraiture. But don’t.