'Spelter' was a British special forces intelligence mission in German-occupied Czechoslovakia (4 May 1944/May 1945).

The undertaking was organised by the intelligence department of the ministry of national defence of the Czechoslovak government-in-exile, and was one of the third wave of such operations. The drop of 4/5 May 1944 involved Captain Bretislav Chrastina, Jaroslav Kotásek, Rudolf Novotny as wireless operator, and other men, and the operation’s task was to support and organise resistance activities, to collect intelligence and to maintain radio contact with London. The men were dropped near Kramolína. Kotásek remained trapped in the harness of his parachute, which was tangled in a tree, and then the parachutes could not be hidden. Chrastina became lost when fording a stream, and meanwhile the Gestapo began to investigate reports of a landing. The other member of the 'Spelter' team met a local resistance unit near Bonova and received temporary shelter, but later two of the men were not accepted when they reached their intended resistance unit. Chrastina failed to link with the rest of the team, but instead managed to reach Slovakia, where he joined the local partisan forces, and Kotásek assumed command of the 'Spelter' mission.

For reasons of security, the party had to leave its equipment in concealment, and was therefore unable to complete its assigned tasks. With the aid of local resistance units, the men of the 'Spelter' mission were also to move into a forest worker’s house near Myslibořice, and on 5/6 June managed to re-establish radio communication with London. During the night of 15/16 June there was a firefight as men of the Gestapo arrived to seize the men of the 'Spelter' mission, and while Novotny and Vavrda managed to escape, Kotásek was killed and others fell into Gestapo hands. Using contacts made before the Gestapo raid, the two surviving member of the 'Spelter' mission managed to hide in Sasovice and then Zeletava, obtain new fake documents and build a makeshift radio to re-establish communication with London. The two men were able to unite 12 different resistance groups, with about 200 members, which operated to the end of the war.